Cooking calculators solve the everyday mathematical challenges of the kitchen: scaling a recipe up or down, converting between volume and weight measurements, calculating cook times for different portion sizes, converting oven temperatures between Celsius and Fahrenheit, and determining the nutritional content of a meal. These tools transform recipe work from guesswork into precision.

Professional chefs measure ingredients by weight rather than volume whenever possible. Weight measurements are more accurate (a "cup" of flour can vary by up to 50% depending on how it is scooped), easier to scale (simply multiply), and faster for large batches. Our cooking calculators support both systems and allow you to convert between them for hundreds of common ingredients.

Scaling a recipe is deceptively tricky. Simply multiplying all ingredient quantities by the scale factor works for most components, but leavening agents (baking powder, baking soda, yeast), salt, and spices generally should not scale linearly — a recipe scaled 4× may need only 3× the salt for the same flavor impact. Similarly, cooking time does not scale linearly with batch size.

Oven temperature conversions are essential when cooking from international recipes. European recipes typically use Celsius (fan/convection oven); American recipes use Fahrenheit (conventional oven). Additionally, the same nominal temperature can produce different results in a conventional vs. convection oven — convection ovens run effectively 25°F (14°C) hotter due to forced air circulation.

Recipe scaling multiplies or divides all ingredient quantities by a uniform factor to produce a different yield. The scaling factor is the ratio of the desired yield to the original yield. If a recipe makes 24 cookies and you want 60, the scaling factor is 60 ÷ 24 = 2.5.

Not all ingredients scale equally well. Leavening agents (baking powder, baking soda) should be scaled at approximately 75% of the linear factor when increasing a recipe by 4× or more; too much leavening creates a coarse, crumbling texture. Salt and seasoning should be added to taste when scaling significantly — flavors concentrate differently in larger batches. Cooking time increases when doubling a recipe in the same pan due to increased thermal mass, but the relationship is not linear.

US cooking measurements use teaspoons (tsp), tablespoons (tbsp), cups, fluid ounces, pints, quarts, and gallons for volume, and ounces and pounds for weight. The relationships are: 3 tsp = 1 tbsp; 16 tbsp = 1 cup; 2 cups = 1 pint; 2 pints = 1 quart; 4 quarts = 1 gallon. One US cup = 237 mL.

Metric cooking uses milliliters (mL) and liters (L) for volume, and grams (g) and kilograms (kg) for weight. An Australian tablespoon is 20 mL (vs. 15 mL in the US), so be careful when cooking from Australian recipes.

Volume-to-weight conversions depend on the ingredient's density. One US cup of all-purpose flour weighs approximately 120–130 g (though scooping directly can give up to 150 g). One cup of granulated sugar weighs about 200 g. One cup of water weighs exactly 236.6 g (= mL × density of water at 1 g/mL). Our converter includes density data for hundreds of common ingredients.

Oven temperatures are the most critical conversion when using international recipes. The formula to convert Fahrenheit to Celsius is: °C = (°F − 32) × 5/9. Common baking temperatures include: 325°F = 163°C (slow/low), 350°F = 177°C (moderate), 375°F = 191°C (moderately hot), 400°F = 204°C (hot), 425°F = 218°C (very hot), and 450°F = 232°C (extremely hot).

Gas mark temperatures are used in UK and Irish recipes: Gas Mark 1 = 275°F = 140°C; Gas Mark 4 = 350°F = 180°C; Gas Mark 7 = 425°F = 220°C. For convection (fan) ovens, reduce the temperature by 25°F (14°C) from a conventional oven setting, or follow your oven manufacturer's guidance.

Food safety depends on reaching internal temperatures that destroy harmful bacteria. The USDA recommends: whole poultry 165°F (74°C); beef, pork, lamb steaks and roasts 145°F (63°C) with a 3-minute rest; ground beef 160°F (71°C); fish 145°F (63°C). These temperatures must be measured with a calibrated food thermometer at the thickest part of the meat, away from bone.

Roasting time for large cuts of meat depends on weight, starting temperature, oven temperature, and desired doneness. A common guideline for a beef roast at 325°F is 20 minutes per pound for medium (145°F internal). However, using a thermometer rather than time alone is always more reliable.