Bread Calculator (Loaf Size)

The calculator works out the internal volume of both tins (length × width × depth), then divides your tin's volume by the original tin's volume to find a scale factor. That scale factor is multiplied by your original dough weight to give the new amount of dough needed. This ensures your dough fills your tin to the same proportion as the original recipe intended.

The tin's wall thickness doesn't hold dough — only the interior does. Measuring the outside dimensions would give you a larger volume than the dough actually occupies, leading to too little dough in the tin. Always use inside base measurements for accurate results.

The standard baker's rule is to fill a loaf tin to about 75% of its volume with dough before proofing. This gives the dough room to rise (proof) and then spring up above the rim during baking, creating a classic domed loaf. Filling too low results in a flat top; filling too high risks overflow.

Loaf tins are often slightly tapered (wider at the top than the base). For best accuracy, measure the inside dimensions at the base of the tin, not the top. The result will be a close approximation; slight variations are normal and won't significantly affect your bake.

Yes. Once you have your scale factor from this calculator, multiply every ingredient in your recipe by that same factor. For example, if your scale factor is 1.35, multiply your flour, water, salt, and yeast quantities all by 1.35 to keep the recipe balanced.

Different bread types behave differently — a dense rye loaf fills a tin differently than a light white sandwich loaf. Hydration level, flour type, and proofing time all affect how much a dough rises and spreads. The calculator gives you an excellent starting point, but some fine-tuning based on experience with your specific recipe may be needed.

This calculator is designed for rectangular loaf tins. For round tins, the volume formula is different (π × r² × height). Applying this tool to non-rectangular tins will give inaccurate results, so it's best used specifically for loaf-shaped bread pans.

Add up all the ingredient weights in your recipe — flour, water, salt, yeast, butter, etc. The total is your dough weight. Baker's percentages can help: if your recipe uses 500g flour at 70% hydration with 10g salt and 7g yeast, your total dough weight would be approximately 500 + 350 + 10 + 7 = 867g.