How to Use This Warp Planner
- Choose your unit system (inches/yards or cm/m) — everything updates instantly.
- Enter your Loom & Warp Settings: EPI, warp width in the reed, loom type (sets a default loom waste), take-up + shrinkage percentage, and the fringe allowed between pieces.
- Set your Weft Settings: PPI, weft take-up, draw-in, and the cone or skein size for each yarn so the shopping list is accurate.
- Add each item you plan to weave on this warp by clicking + Add Piece. Enter the finished length, finished width, quantity, and any fringe at the ends. Override PPI per piece if needed.
- Read the results instantly: total warp length, total warp ends, warp yardage, weft yardage, and how many cones or skeins to buy.
When & Why Plan a Multi-Piece Warp
Putting multiple items on one warp is standard practice in handweaving. You only incur loom waste once regardless of how many items you weave, saving material and warping time. A set of four kitchen towels on a single warp wastes roughly the same length as one towel would on its own warp — that's three towels' worth of loom waste saved.
Planning ahead also protects you from running out of yarn mid-project or buying too little. Running out is especially painful when yarns are hand-dyed in small batches or seasonal colourways where a matching dye lot may no longer be available.
Formula & Method
This planner uses the formulas described by Handwoven Magazine / The Weaver's Companion and Gist Yarn, the standard references in handweaving yardage planning.
woven_length = finished_length ÷ (1 − takeup%/100)Total warp length:
total_warp = Σ(pieces: qty × woven_length + fringe_both_ends) + fringe_between × (pieces−1) + loom_wasteTotal warp ends:
ends = EPI × warp_width_in_reedTotal warp yardage:
warp_yards = ends × total_warp ÷ 36 (÷ 100 for metres)Weft yardage per piece:
weft = PPI × weave_width × woven_length × (1 + weft_takeup%/100) ÷ 36where
weave_width = finished_width ÷ (1 − draw_in%/100)
A safety buffer (default 10%) is added to the final total before computing how many cones or skeins to buy. The buffer helps guard against sampling waste, mismeasured fringe, and small differences between your yarn's actual yardage and the label.
Frequently Asked Questions
How do I calculate warp length for multiple pieces on one warp?
Add the woven length of each piece (which is the finished length divided by (1 − take-up%), then multiplied by the quantity), plus fringe at each end, plus fringe separators between pieces, plus your loom's total loom waste. This planner does all that automatically as you add pieces.
What percentage should I use for take-up and shrinkage?
A common starting point is 10–15% combined. Cotton and linen typically need around 10%; wool or heavily beaten fabrics may need 15–20%. For the most accurate number, weave and wet-finish a small sample, measure before and after, and use the ratio. Gist Yarn recommends 10–15% as a default for most balanced plain-weave projects.
How much loom waste should I add?
Most floor looms have 27–36 inches of total loom waste (the warp you cannot weave because of the tie-on at the front apron rod plus the distance between the heddles and back beam). Rigid heddle looms typically need about 18 inches. This planner defaults to loom-type presets, but you can enter your own measurement for the most accuracy.
How do I calculate weft yardage?
Weft yardage = picks per inch × weaving width × woven length ÷ 36 (in yards), plus about 10% for the interlacement angle (weft take-up). The weaving width is typically 5–10% wider than the finished width because the weft draws the selvedges inward — this is draw-in. The planner accounts for both.
Why plan multiple items on the same warp?
You only pay loom waste once regardless of how many pieces you put on the warp. For a set of four towels, putting them on a single warp instead of four separate warps can save 60–90 inches (about 1.7–2.5 yards) of warp yarn. You also save significant warping and tie-on time, which is especially valuable for longer warp sequences.
Do all pieces on the warp need the same EPI?
Yes — the EPI (sett) is set at the loom and is constant across the entire warp. You cannot change EPI mid-warp without re-sleying the reed. However, you can change PPI (weft density) between pieces, which is why this planner allows a per-piece PPI override.
Should I add extra yarn beyond the calculated amount?
Yes, always. The default safety buffer of 10% helps cover sampling (which any good weaver does before the main project), unexpected fringe extension, slight mismatch between the label yardage and the actual cone, and the risk of a dye-lot change. Running out mid-project is far worse than having a few extra yards.