# Planning Calculations ## Planning Tab: Complete Weaver's Guide This guide explains every field and calculation in the **Planning** tab of the Project Information dialog. The Planning tab helps you determine how much yarn you need, how long your warp should be, and what your finished dimensions will be after all the inevitable losses that occur during weaving and finishing. *** ### Overview The Planning tab is organized into three columns: * **Left Column**: What your current project looks like (thread counts, dimensions) and the final yarn requirements * **Middle Column**: The adjustment factors that account for real-world losses (take-up, shrinkage, draw-in, loom waste) and multi-piece planning * **Right Column**: A reverse calculator that works backward from your desired finished size to tell you what you need on the loom All calculations update automatically as you change values. The **Yarn Required** section requires you to click the **Calculate Yarn** button after entering your Planned Warp Length. *** ### Units: English vs. Metric At the top Setup Tab on the Project Information dialog, you can choose between **English** and **Metric** units. This affects every measurement in the Planning tab: | Measurement Type | English | Metric | | ------------------- | ------------------- | ------------------ | | Density (sett/beat) | EPI (ends per inch) | EPCM (ends per cm) | | Short distances | inches (in) | centimeters (cm) | | Long distances | yards (yds) | meters (m) | When you switch units, all values are automatically converted. The conversion factors are: * **Density**: EPI / 2.54 = EPCM * **Short distances**: inches x 2.54 = cm * **Long distances**: yards x 0.9144 = meters Internally, short distances (inches or cm) are converted to long distances using: * **English**: divide by 36 (36 inches = 1 yard) * **Metric**: divide by 100 (100 cm = 1 meter) *** ### Left Column #### Current WIF Info This section shows dimensions derived from your actual weaving draft. These are **read-only** values calculated from the threads and picks in your project. **Warp Ends** The total number of warp threads that have been assigned to a shaft. TempoWeave counts every thread in your threading that has a shaft value greater than zero. Empty or unassigned threads are not counted. **Width in Reed** How wide your warp will be in the reed, calculated as: ``` Width in Reed = Warp Ends / Sett ``` For example, 480 ends at 24 EPI = 20 inches in the reed. *The Width in the reed may be overridden. For example, you may have a threading of 2 warp ends for plain weave that you want to repeat for 40 inches in the reed; by entering the override, the Width in the Reed will will be changed to the override width for calculations without needing to modify the current WIF.* **Weft Picks** The total number of weft picks (rows) that contain treadling or liftplan data. In **treadling mode**, this counts picks with a treadle assigned. In **liftplan mode**, this counts picks where at least one shaft is raised. **Woven Length** How long your cloth will be on the loom before any finishing, calculated as: ``` Woven Length = Weft Picks / Beat ``` For example, 360 picks at 18 PPI = 20 inches of woven cloth. *The Woven Length may be overriden for purposes of yarn and finished size calculations. For example, if you don't choose to enter the picks for a very long piece, the length may be entered as an override for purposes of finished width and yarn calculations. Be aware that if weft colors change, the weft yardage by color may not be correct.* **Finished Est. Width** An estimate of your finished width after draw-in and shrinkage: ``` Finished Est. Width = (Effective Width - Draw-In) x (1 - Width Shrinkage / 100) ``` Where **Effective Width** is either the Width in Reed or the Override Width (if you entered one). **Example**: 20 in width, 0.5 in draw-in, 5% shrinkage = (20 - 0.5) x 0.95 = 18.53 in **Finished Est. Length** An estimate of your finished length after shrinkage: ``` Finished Est. Length = Effective Woven Length x (1 - Length Shrinkage / 100) ``` Where **Effective Woven Length** is either the calculated Woven Length or the Override Woven Length (if you entered one). **Example**: 20 in woven length, 8% shrinkage = 20 x 0.92 = 18.40 in #### Overrides The two override fields let you manually specify the width in reed or woven length instead of using the values calculated from your draft. This is useful when: * You do not intend to complete the entire draft for a simple repeating pattern. * You are planning a project before you have completed the full draft When an override is set to a value greater than zero, it replaces the corresponding calculated value in **all** subsequent calculations (finished estimates, min warp length, yarn requirements). *** #### Warp Length This section helps you determine how much warp to put on your loom. **Min Warp Length (calculated)** The minimum warp length you need to weave your project, accounting for all losses. This is the most important planning number: ``` Min Warp Length = ( ((Woven Length per Piece x (1 + Warp Take-up%/100)) + Fringe) x Pieces + (Sampling x (1 + Warp Take-up%/100)) + Loom Waste ) / Unit Divisor ``` Where **Unit Divisor** is 36 (English, converting inches to yards) or 100 (Metric, converting cm to meters). Let's break this down piece by piece: 1. **Woven length adjusted for take-up**: `Woven Length x (1 + Warp Take-up%/100)` — this is how much warp each piece actually consumes, because the warp threads travel up and over the weft, using more thread than the flat cloth length 2. **Add fringe**: Fringe length is added per piece (total for both ends) 3. **Multiply by pieces**: If you are weaving multiple pieces from one warp 4. **Add sampling with take-up**: Sampling warp is only counted once (not per piece), but also needs the take-up adjustment 5. **Add loom waste**: The fixed amount of warp you cannot weave — this is counted once regardless of how many pieces you weave **Example (English units)**: * Woven length per piece: 72 in (2 yards) * Warp take-up: 10% * Fringe: 8 in (total both ends) * Pieces: 2 * Sampling: 12 in * Loom waste: 27 in ``` Min Warp = (((72 x 1.10) + 8) x 2 + (12 x 1.10) + 27) / 36 = ((79.2 + 8) x 2 + 13.2 + 27) / 36 = (174.4 + 13.2 + 27) / 36 = 214.6 / 36 = 5.96 yards ``` **Planned Warp Length (you enter this)** This is where you enter how much warp you actually plan to put on the loom. It should be **at least** as much as the Min Warp Length — ideally a bit more to give yourself a safety margin. This value is critical for the **Yarn Required** calculation. If you leave it at zero, the yarn calculation will show zero. **Tip**: Most weavers add 10-15% to the minimum warp length for safety. You can also round up to a convenient number. **Tip:** If using the loom waste at the beginning and end for fringe, there is no need to enter the fringe value. **Total Woven (calculated)** The total length of cloth you will weave across all pieces plus sampling: ``` Total Woven = (Woven Length per Piece x Pieces + Sampling) / Unit Divisor ``` This does **not** include take-up, fringe, or loom waste — it is strictly how much woven cloth you will produce when measured without tension and before wet finishing. *** #### Yarn Required This section calculates how much warp and weft yarn you need for your project. It is highlighted in a colored box because these are the numbers you take to the yarn store. You must click the **Calculate Yarn** button after entering your Planned Warp Length. The values also update when you change other planning inputs. **Warp Required** The total amount of warp yarn needed: ``` Warp Required = Warp Ends x Planned Warp Length + Floating Selvedge Yarn ``` Where **Floating Selvedge Yarn** accounts for any floating selvedge threads configured on the Setup tab: ``` Floating Selvedge Yarn = Selvedge Thread Count x Planned Warp Length ``` The selvedge thread count depends on your settings: * Right floating selvedge: adds 1 thread (or 2 if "double" is checked) * Left floating selvedge: adds 1 thread (or 2 if "double" is checked) **If you have entered an Override Width**: The warp required is calculated differently — it uses the override width multiplied by the sett to determine the thread count, rather than counting actual threads from the draft: ``` Warp Required = Override Width x Sett x Planned Warp Length + Floating Selvedge Yarn ``` The result is expressed in **yards** (English) or **meters** (Metric). This is the total length of yarn across all threads. To convert to weight or skeins, you will need to know your yarn's yardage per pound or meters per kilogram (available in the Yarn Catalog). **Example (English units)**: * 480 warp ends * Planned warp length: 6 yards * Right floating selvedge (single): 1 thread ``` Warp Required = 480 x 6 + 1 x 6 = 2,880 + 6 = 2,886 yards ``` **Weft Required** The total amount of weft yarn needed: ``` Weft Required = Beat x Effective Width x Total Woven Length x (1 + Weft Take-up%/100) ``` Where: * **Effective Width** = Width in Reed - Draw-In (this is how wide the cloth actually is after the edges pull in) * **Total Woven Length** = (Woven Length per Piece x Pieces + Sampling) / Unit Divisor * **Weft Take-up** accounts for the weft thread traveling over and under the warp threads **Example (English units)**: * Beat: 18 PPI * Width in Reed: 20 in, Draw-In: 0.5 in, Effective Width: 19.5 in * Woven length per piece: 72 in, 2 pieces, 12 in sampling * Total Woven = (72 x 2 + 12) / 36 = 4.33 yards * Weft take-up: 8% ``` Weft Required = 18 x 19.5 x 4.33 x 1.08 = 1,641 yards ``` *** ### Middle Column #### Calculation Drivers These are the adjustment factors that account for real-world losses during weaving and finishing. If you leave them all at zero, your calculations will show the "ideal" dimensions with no losses — but real cloth usually shrinks in width and length. **Draw-In** **Unit**: inches or cm The total width lost at the selvedges when the weft pulls the outer warp threads inward. On a typical project this is usually 0.25 to 1 inch (0.5 to 2.5 cm), depending on: * Weave structure (plain weave draws in more than twill) * Yarn elasticity (stretchy yarns draw in more) * Sett (closer setts draw in less) * Width (wider warps may draw in more in absolute terms) Draw-in is subtracted from the width in reed to get the woven width, and it is added back when calculating the required width in the Target Calculator. **Warp Take-up** **Unit**: percentage (%) The percentage of warp thread consumed by the over-and-under interlacement. Because the warp threads do not lie flat — they go over and under each weft pick — you need more warp thread than the flat cloth length. Typical values: * **Plain weave**: 10-12% (most interlacement, most take-up) * **Twill**: 8-10% * **Satin**: 5-8% (least interlacement, least take-up) Warp take-up is applied to the woven length and sampling when calculating the minimum warp length. It does **not** apply to fringe or loom waste. **Weft Take-up** **Unit**: percentage (%) The percentage of extra weft thread consumed by interlacement, similar to warp take-up but in the horizontal direction. Because the weft travels over and under the warp threads, each pick uses more yarn than the straight-line width of the cloth. Typical values: * **Plain weave**: 10-15% * **Twill**: 8-12% * **Satin**: 5-8% Weft take-up is applied to the weft yarn requirement only. It does not affect finished dimensions. **Loom Waste** **Unit**: inches or cm The length of warp that cannot be woven because it is consumed by the loom setup — the distance from the back beam to the heddles, through the reed, to the cloth beam. This includes: * Warp tied to the front apron rod * Warp between the heddles and the back beam that cannot be shed properly * Any lashing or knots Typical values: * **Table looms**: 18-27 inches (45-70 cm) * **Floor looms**: 24-36 inches (60-90 cm) * **Rigid heddle looms**: 12-18 inches (30-45 cm) Loom waste is counted **once** regardless of how many pieces you weave. It is simply added to the total warp length needed. **Width Shrinkage** **Unit**: percentage (%) The percentage the cloth shrinks in width after it comes off the loom and is washed/finished. This is different from draw-in — draw-in happens during weaving, while shrinkage happens during wet finishing. Typical values: * **Cotton**: 5-10% * **Wool**: 10-30% (depending on fulling) * **Linen**: 3-5% * **Silk**: 3-8% * **Synthetic blends**: 2-5% Width shrinkage is used in the finished estimate and the target calculator. **Length Shrinkage** **Unit**: percentage (%) The percentage the cloth shrinks in length after finishing. Often different from width shrinkage because warp and weft may be different fibers or have different tensions. Typical values are similar to width shrinkage but may vary. Always do a sample to determine your actual shrinkage — it depends heavily on your specific yarn, sett, and finishing method. Length shrinkage is used in the finished estimate and the target calculator. *** #### Length Drivers These fields help you plan multi-piece projects and account for additional warp length needs. **Fringe Total** **Unit**: inches or cm The total fringe length for **both ends** of each piece combined. If you want 4 inches of fringe on each end, enter 8. Fringe is part of the warp that is not woven — it hangs off the ends of the cloth. It is added to each piece's warp requirement but does **not** have warp take-up applied (since it is not interlaced). **Sampling** **Unit**: inches or cm The length of warp set aside for weaving a sample or test piece before starting your main project. Sampling is counted **once** on the warp (not multiplied by the number of pieces), and warp take-up **is** applied to it (since you are weaving it). In the weft calculation, sampling is also included in the total woven length. **Pieces** **Unit**: count (integer) The number of identical pieces you plan to weave from this warp. For example, if you are weaving a set of 4 placemats, enter 4. Each piece uses one full woven length plus fringe. The total warp needed is calculated for all pieces together, sharing a single loom waste and sampling allowance. *** ### Right Column #### Target Finished Size This section works **backwards** from your desired finished dimensions. Instead of asking "given my draft, how big will my finished cloth be?", it answers "given my desired finished size, how many threads and picks do I need?" Enter the finished width and length you want **after** shrinkage and draw-in, and the calculator will tell you what you need on the loom. **Finished Width** **Unit**: inches or cm The width you want your finished cloth to be after all draw-in and shrinkage. This is the final, usable width. **Finished Length per Piece** **Unit**: inches or cm The length you want each finished piece to be after shrinkage. This is the final, usable length per piece. *** #### Calculated Results These are the results of the reverse calculation, shown in a highlighted box. They tell you what you need on the loom to achieve your target finished size. **Required Width in Reed** The width your warp needs to be in the reed to achieve the target finished width: ``` Required Width in Reed = (Finished Width + Draw-In) x (1 + Width Shrinkage%/100) ``` This reverses the shrinkage and draw-in: it adds the draw-in back (because the reed width must be wider than the finished width), and then accounts for shrinkage (because the cloth will shrink after finishing). **Example**: Target finished width 18 in, draw-in 0.5 in, 5% width shrinkage: ``` Required Width = (18 + 0.5) x 1.05 = 19.43 in ``` **Required Warp Ends** The number of warp threads needed to achieve the required width in reed: ``` Required Warp Ends = Required Width in Reed x Sett ``` **Example**: Required width 19.43 in at 24 EPI: ``` Required Warp Ends = 19.43 x 24 = 466 ends ``` You would typically round this up to the nearest number that works with your threading repeat. **Woven Length per Piece** The length you need to weave on the loom (before finishing) to get your target finished length: ``` Woven Length per Piece = Finished Length x (1 + Length Shrinkage%/100) ``` This reverses the shrinkage: the woven cloth needs to be longer than the finished length because it will shrink. **Example**: Target finished length 18 in, 8% length shrinkage: ``` Woven Length = 18 x 1.08 = 19.44 in ``` **Required Weft Picks** The number of weft picks needed for one piece: ``` Required Weft Picks = Woven Length per Piece x Beat ``` **Example**: Woven length 19.44 in at 18 PPI: ``` Required Weft Picks = 19.44 x 18 = 350 picks ``` *** ### Putting It All Together: A Complete Example Let's walk through a full planning scenario for a set of cotton placemats. **Goal**: 4 placemats, each 14 x 18 inches finished, with 3-inch fringe on each end **Known values**: * Yarn: 8/2 cotton at 24 EPI sett, 20 PPI beat * Draw-in: 0.5 inches * Warp take-up: 10% * Weft take-up: 12% * Loom waste: 27 inches * Width shrinkage: 5% * Length shrinkage: 8% * Sampling: 10 inches #### Step 1: Target Calculator Enter the finished dimensions (14 x 18 inches) in the Target Finished Size section. **Required Width in Reed**: (14 + 0.5) x 1.05 = **15.23 in** **Required Warp Ends**: 15.23 x 24 = **366 ends** (round to 368 to fit a 4-thread repeat) **Woven Length per Piece**: 18 x 1.08 = **19.44 in** **Required Weft Picks**: 19.44 x 20 = **389 picks** #### Step 2: Draft Your Project Thread 368 ends and treadle 389 picks per placemat (or as close as your pattern allows). #### Step 3: Min Warp Length With your draft entered, the Current WIF section will show your actual thread and pick counts. The Min Warp Length calculation: ``` Min Warp = (((19.44 x 1.10) + 6) x 4 + (10 x 1.10) + 27) / 36 = ((21.38 + 6) x 4 + 11.0 + 27) / 36 = (109.54 + 11.0 + 27) / 36 = 147.54 / 36 = 4.10 yards ``` (Fringe is 6 inches per piece — 3 inches each end, entered as 6 total.) #### Step 4: Plan Your Warp Enter **4.5 yards** as your Planned Warp Length (adding about 10% safety margin). #### Step 5: Calculate Yarn Click **Calculate Yarn**: **Warp Required**: 368 x 4.5 = **1,656 yards** **Weft Required**: 20 x (15.23 - 0.5) x ((19.44 x 4 + 10) / 36) x 1.12 = 20 x 14.73 x 2.44 x 1.12 = **805 yards** #### Summary | Item | Value | | -------------------- | ------------ | | Warp ends | 368 | | Width in reed | 15.23 in | | Picks per placemat | 389 | | Min warp length | 4.10 yds | | Planned warp length | 4.50 yds | | Warp yarn needed | 1,656 yds | | Weft yarn needed | 805 yds | | Finished size (each) | \~14 x 18 in | *** ### Tips and Best Practices #### Sample First The shrinkage and take-up percentages above are estimates. Every yarn, sett, and weave structure combination behaves differently. Weave a small sample, measure it before and after washing, and calculate your actual percentages before planning a large project. Use the **Sampling** field to allocate warp for this. #### Measuring Weft Take-Up Usually it's not necessary to measure the actual take-up percentage, but if it's critical to understand for a more accurate warp and weft requirements, it can be measured. For weft takeup, weave a couple of inches, carefully marking or cutting the beginning and ending of the weft used. Multiply the Width Woven by the Number of Picks for the total woven inches for the Weft Used before Takeup. Unweave the section just woven, and measure the weft yarn. The Difference in the calculation of the weft used and the Actual Measured yarn is the used for the takeup percentage. Divide this Difference by the Weft Used before Takeup for the takeup percentage. Warp take-up is more difficult to measure. Generally the same value for the weft takeup can be used for the warp take-up percentage. #### Measuring Shrinkage To measure shrinkage from a sample that has been cut off the loom. 1. Measure the relaxed (off-loom, before washing) dimensions 2. Wash and finish the sample as you plan to finish the final project 3. Shrinkage % = (Before washing - After washing) / Before washing x 100 #### Loom Waste Varies Measure your own loom's waste by noting how much warp you cannot weave. This varies between looms and even between warp setups on the same loom. Once you know your loom, you can use the same value for every project.