Leather Wallet Pattern Size Calculator
Calculate leather piece dimensions for bifold, trifold, and card wallets with seam allowances and material needs.
Wallet construction requires precise measurements because leather does not stretch or forgive like fabric. Every piece must account for the thickness of cards, bills, and the leather itself — otherwise the finished wallet will be too tight to close or too loose to hold cards securely.
Standard Wallet Dimensions
Credit cards measure 3.375 × 2.125 inches (85.6 × 53.98 mm) worldwide per the ISO/IEC 7810 ID-1 standard. US bills measure 6.14 × 2.61 inches (156 × 66 mm). These are your anchor measurements.
| Wallet Style | Closed Size (W × H) | Open Flat Size |
|---|---|---|
| Bifold | 4.25 × 3.5" | 8.5 × 3.5" |
| Trifold | 3.0 × 3.5" | 9.0 × 3.5" |
| Card Wallet (slim) | 4.0 × 2.75" | 4.0 × 5.5" |
| Long / Breast Wallet | 7.0 × 3.75" | 7.0 × 7.5" |
Seam Allowance Formula
Cut Size = Finished Size + (2 × Seam Allowance)
| Stitch Type | Seam Allowance | Notes |
|---|---|---|
| Hand-stitched (saddle stitch) | 3–4 mm (⅛") | Minimum for clean stitching line |
| Machine-stitched | 5–6 mm (¼") | Needs more room for presser foot |
| Edge-folded (no stitch) | 8–10 mm (⅜") | For folded-edge card slots |
Leather Thickness Considerations
| Component | Recommended Thickness | Leather Weight |
|---|---|---|
| Outer shell | 1.0–1.2 mm | 2.5–3 oz |
| Card slots | 0.6–0.8 mm | 1.5–2 oz |
| Bill compartment divider | 0.6–0.8 mm | 1.5–2 oz |
| Lining (if used) | 0.4–0.6 mm | 1–1.5 oz |
Worked Example — Bifold Wallet with 6 Card Slots
Outer shell: 8.5" × 3.5" + (2 × 0.125") seam = 8.75" × 3.75" Card slot pieces (3 per side, overlapping):
- Bottom slot: 4.0" × 2.5" (fully exposed)
- Middle slot: 4.0" × 2.0" (overlaps bottom by 0.75")
- Top slot: 4.0" × 2.0" (overlaps middle by 0.75")
Add 0.125" seam allowance to each piece on three sides (left, right, bottom). Top edge is folded.
Total leather needed: approximately 1.5 square feet of 2.5–3 oz leather for the shell, plus 1 square foot of 1.5–2 oz leather for card slots and dividers.
Fold Compensation
When leather folds, the outer layer stretches and the inner layer compresses. For each fold, add:
Fold Compensation = π × Leather Thickness × Number of Folds
For a bifold with 1.0 mm leather: π × 1.0 mm × 1 fold = 3.14 mm (~⅛") added to the outer shell length.
For a trifold with 1.0 mm leather: π × 1.0 mm × 2 folds = 6.28 mm (~¼") total.
This small addition prevents the wallet from splaying open when loaded with cards.