The kitchen calculators
you actually need.

Free, instant, no signup. Get the right ratios, conversions, and scaling for whatever you're making.

Coffee

Coffee Ratio Calculator

The right grams of coffee for any brew method.

500g water · French Press
→ 31g coffee · 1:16 ratio
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Baking

Pan Size Converter

Substitute any baking pan with confidence.

9" round → 8" square pan
→ Scale recipe to 0.95×
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Cooking

Recipe Scaler

Double, halve, or scale by any factor.

4 servings → 8 servings
→ Multiply every ingredient by 2.0×
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Altitude

High Altitude Adjustment

For baking above 3,000 ft.

Recipe at 5,280 ft (Denver)
→ +25°F · +2 tbsp liquid · less leavening
Open calculator →

Why KitchenMath

Cooking is half intuition, half measurement. The intuition you build over years. The measurement you can fix in 30 seconds — once you have the right tool.

This site is just the calculators. No 1,500-word origin story before you can find the answer. No newsletter popup. No "click to reveal." Just the math, with explanations underneath if you want them.

— Maya