Cooking measurement conversion looks like the simplest kind of math — until you remember that a "cup" can mean two different volumes depending on which country wrote the recipe, and that converting volume to weight isn't really a conversion at all without knowing what you're measuring.
Volume vs. Weight: Why a Cup of Flour Isn't a Cup of Sugar
A pure volume converter — teaspoons, tablespoons, cups, milliliters — works the same way a measuring cup itself works, regardless of what's inside it. But a cup of flour and a cup of granulated sugar don't weigh the same amount, because they pack differently: flour is lighter and airier, sugar is denser. Converting a volume measurement to a weight measurement like grams isn't a fixed ratio at all — it requires knowing the specific ingredient's density, which is why recipes that give weights for dry ingredients are usually more precise than ones that only give cup measurements.
US Cups vs. Metric Cups
A US customary cup is defined as exactly 236.588 milliliters. Several other countries use a slightly different "metric cup," typically defined as 250 milliliters — close enough to cause only minor differences in most recipes, but enough to matter in baking, where ratios are more sensitive. If a recipe doesn't specify which cup it means, it's worth checking the source's country of origin before assuming.
How Oven Temperature Conversion Works
Converting Fahrenheit to Celsius uses one exact formula: °C = (°F − 32) × 5/9 (and the reverse: °F = °C × 9/5 + 32). This math is precise — there's no approximation involved. Any real-world discrepancy between a recipe's stated temperature and how your food actually bakes comes from your specific oven's calibration, not from any rounding in the conversion itself.
Teaspoons, Tablespoons, and the Math Between Them
Two ratios are worth memorizing because they come up constantly: 3 teaspoons make 1 tablespoon, and 16 tablespoons make 1 US cup. Unlike the volume-to-weight problem above, these are fixed relationships that never change regardless of what you're measuring, since they're all still just units of volume.
Convert Instantly
Convert between teaspoons, tablespoons, cups, milliliters, and more, or flip an oven temperature between Fahrenheit and Celsius, with our free Cooking Measurement Converter.
FAQ
Does this account for different ingredient densities, like cups of flour vs. cups of water? No — this converts pure volume units only (teaspoons, tablespoons, cups, milliliters, and so on), the same way a measuring cup itself works. Converting to a weight measurement like grams would require knowing the specific ingredient's density, which varies a lot between flour, sugar, butter, and liquids.
Are these US or metric cup sizes? US customary units — a US cup is defined as 236.588 milliliters. Some countries use a slightly different "metric cup" (250 mL), so double-check which your recipe means if it doesn't specify.
How accurate is the oven temperature conversion? It uses the exact standard formula (°C = (°F − 32) × 5/9), which is mathematically precise — any real-world difference would come from your specific oven's calibration, not the conversion math.
How many tablespoons are in a cup? 16 tablespoons make one US cup, and 3 teaspoons make one tablespoon — both are fixed volume ratios, unlike a cup-to-gram conversion, which changes depending on what you're measuring.