# Bag Calculator (Tote Bag Pattern)

URL: https://speedycalculator.com/calculators/everyday-life/bag/
Last updated: 2026-10-25

> The bag calculator works out the size of fabric to cut for a tote or shopping bag from its finished height, width and depth, with or without boxed corners and seam allowances.

## Inputs

- Finished height (in, cm)
- Finished width (in, cm)
- Depth (gusset) (in, cm)
- Boxed corners
- Seam allowance (in, cm)
- Top hem allowance (in, cm)

## Results

- Width of each panel
- Height of each panel
- One-piece cut (folded at the bottom)
- Corner square to cut out
- Fabric area for two panels

## Formula

```
Fabric width = 2 × width + 2 × depth + 2 × seam allowance
Fabric height = height + depth ÷ 2 + seam allowance + hem
Boxed corner square = depth ÷ 2
```

## Explanation

A simple tote is cut from one long rectangle folded at the bottom, or from two panels sewn together. To give the bag a flat base, the bottom corners are "boxed": you sew across each corner so the bag gains depth. The fabric needs to be wide enough to wrap around the front, back and both sides, plus seams.

### How to use the Bag Calculator

- **Finished height**
- **Finished width**
- **Depth (gusset)**
- **Boxed corners**
- **Seam allowance**
- **Top hem allowance**

Results update as you type, and every field accepts the units shown in its menu.

### How it works

Enter the finished height, width and depth of the bag, whether it has boxed corners, your seam allowance and the hem at the top. The calculator gives the size of each of the two panels and the square to cut out of the corners.

### Tips

- Measure over thin clothing with a soft tape held snug but not tight, and keep the tape level all the way round.
- Take each measurement twice; if you are between sizes, the larger size is usually the safer choice.
- Size charts vary by brand and country – check the maker's own chart when it is available.
- For sewing projects, pre-wash fabric before cutting and buy 10% extra for shrinkage, pattern matching and mistakes.

### Common mistakes to avoid

- Mixing inches and centimetres between the tape and the size chart.
- Forgetting seam and hem allowances when cutting fabric.
- Measuring an old, stretched garment instead of your body.

### Inputs explained

FieldWhat to enterFinished heightUnits: in, cmFinished widthUnits: in, cmDepth (gusset)Units: in, cmBoxed cornersChoose one: No, YesSeam allowanceUnits: in, cmTop hem allowanceUnits: in, cm

### What each result means

- **Width of each panel** = [Finished width] + [Boxed corners]×[Depth (gusset)] + 2×[Seam allowance]
- **Height of each panel** = [Finished height] + [Boxed corners]×[Depth (gusset)]÷2 + [Seam allowance] + [Top hem allowance]
- **One-piece cut (folded at the bottom)** = 2×[Height of each panel] - 2×[Seam allowance]
- **Corner square to cut out** = [Boxed corners]×[Depth (gusset)]÷2
- **Fabric area for two panels** = 2×[Width of each panel]×[Height of each panel]

### Example values

How the main result changes when **Finished height** changes and everything else stays at the example values above:

Finished height (in)Width of each panel (in)7.51811.2518151818.751822.5183018

## Worked example

Inputs — Finished height: 15 in; Finished width: 13 in; Depth (gusset): 4 in; Boxed corners: Yes; Seam allowance: 0.5 in; Top hem allowance: 1 in.

Results — **Width of each panel = 18 in**; Height of each panel = 18.5 in; One-piece cut (folded at the bottom) = 36 in; Corner square to cut out = 2 in; Fabric area for two panels = 666 in².

## Key terms

- **Gusset**: The side and bottom depth of a bag.

## FAQ

**How big should a tote bag be?**
A typical shopping tote is about 15 × 16 in with a 4–5 in gusset; a book bag 13 × 15 in.

**What is a boxed corner?**
A seam sewn across each bottom corner to create a flat base; the depth of the base equals twice the cut-out square.

**Should I line my tote?**
A lining hides seams and adds strength – cut it the same size as the outer panels.

**What formula does the Bag Calculator use?**
Fabric width = 2 × width + 2 × depth + 2 × seam allowance.