How to Convert a Recipe to Metric
Converting a US recipe to metric involves three things: switching volume measurements (cups, tablespoons) to weight (grams), converting oven temperature from Fahrenheit to Celsius, and converting any pan sizes from inches to centimeters. The biggest source of error is treating cups as a universal unit — a cup of flour and a cup of honey have very different weights, so each ingredient needs its own gram conversion. This guide covers everything you need to write or follow recipes in metric measurements confidently, whether you're cooking from a US recipe abroad or converting your own recipes for an international audience.
Step 1: Convert Volume to Weight, Ingredient by Ingredient
This is the part people get wrong most often. "1 cup" means a different weight depending on what's in it. You cannot use a single multiplier for the whole recipe — each ingredient needs its own conversion based on its density.
| Ingredient | 1 cup = |
|---|---|
| All-purpose flour | 120-125g |
| Granulated sugar | 200g |
| Brown sugar (packed) | 200g |
| Butter | 227g |
| Milk | 240g |
| Honey | 340g |
| Rolled oats | 90g |
| Powdered sugar | 120g |
For ingredients not listed here, use the Cups to Grams Calculator, which covers a wide range of common baking ingredients with their individual density conversions.
Step 2: Convert Oven Temperature
US recipes use Fahrenheit; metric recipes use Celsius. The formula is °C = (°F − 32) × 5/9, but for everyday baking, these rounded reference points cover almost everything you'll need:
| °F | °C | Gas Mark (UK) |
|---|---|---|
| 300°F | 150°C | 2 |
| 325°F | 165°C | 3 |
| 350°F | 175°C | 4 |
| 375°F | 190°C | 5 |
| 400°F | 200°C | 6 |
| 425°F | 220°C | 7 |
| 450°F | 230°C | 8 |
For exact figures or temperatures not listed, use the Oven Temperature Converter.
Step 3: Convert Pan Sizes
US recipes give pan dimensions in inches; metric recipes use centimeters. The conversion is straightforward (1 inch = 2.54cm), but pan size affects baking time and texture, so getting it right matters more than it might seem.
| US (inches) | Metric (cm) |
|---|---|
| 8-inch round | 20cm round |
| 9-inch round | 23cm round |
| 9×13-inch | 23×33cm |
| 8×8-inch square | 20×20cm square |
| Loaf pan (9×5-inch) | 23×13cm |
If the exact size isn't available, round to the nearest standard size rather than using an odd in-between size — most metric bakeware comes in fixed sizes similar to US pans, just in centimeters.
Step 4: Convert Weight-Based Ingredients (Meat, Produce)
Some ingredients are already given by weight in US recipes (ounces, pounds) rather than volume. These convert directly without needing density figures: 1 oz = 28.35g, 1 lb = 453.6g. Use the Weight Converter for quick conversions of any amount.
Step 5: Convert Liquid Volumes to Milliliters
Liquids (milk, water, stock, oil) convert on a fixed ratio since density doesn't vary the way it does for dry ingredients like flour or sugar. Use these reference points:
| US Volume | Metric |
|---|---|
| 1 teaspoon | 5 ml |
| 1 tablespoon | 15 ml |
| 1 cup | 237 ml |
| 1 pint (2 cups) | 473 ml |
| 1 quart (4 cups) | 946 ml (≈1 liter) |
For a full breakdown of quarts, pints, and gallons in cups and liters, see how many cups in a quart, pint, and gallon.
Worked Example: Converting a Full Recipe
Take a simple pancake recipe: 2 cups flour, 2 tbsp sugar, 2 tsp baking powder, 1¼ cups milk, 1 egg, baked in an 8-inch pan reference (though pancakes don't need a pan size, this shows the pattern). Converting each line individually:
- 2 cups flour → 2 × 125g = 250g flour
- 2 tbsp sugar → 2 × 15ml ≈ 25g sugar (sugar's density is close enough to volume-for-weight at this small amount)
- 2 tsp baking powder → 2 × 5ml = 10ml baking powder (small leavening amounts are usually left in ml/tsp even in metric recipes)
- 1¼ cups milk → 1.25 × 237ml ≈ 296ml milk
- 1 egg → no conversion needed, eggs are counted, not measured by volume
Notice that each ingredient used its own conversion factor rather than one blanket multiplier — this is the core discipline of converting a recipe correctly.
Why Weight Is More Reliable Than Volume
If you're converting a recipe to metric anyway, this is a good opportunity to switch to weighing ingredients entirely rather than using cup measurements. Weight is more precise — a cup of flour can vary by 20-25g depending on how it's scooped, but 125g of flour is always 125g. Most professional and European bakers weigh ingredients for this reason. If you have a kitchen scale, converting a recipe to grams once means you'll get consistent results every time you make it.
Frequently Asked Questions
Can I just use one conversion factor for the whole recipe?
No. Each ingredient has a different density, so "1 cup" represents a different gram weight depending on whether it's flour, sugar, butter, or liquid. Using a single multiplier for an entire recipe will throw off the ratios between ingredients. Convert each ingredient individually using its specific weight-per-cup.
What's the easiest way to convert an entire recipe at once?
Go ingredient by ingredient using a cups-to-grams reference for each one, rather than trying to do mental math for the whole list at once. Write the gram amount next to each original measurement so you can double-check your converted recipe before baking. For volume measurements like tablespoons and teaspoons that don't need ingredient-specific conversion (most liquids, spices), a simple multiplier (1 tbsp = 15ml) works fine.
Do I need to convert teaspoons and tablespoons to metric too?
For small amounts like spices, leavening agents, and extracts, most metric recipes still use teaspoons and tablespoons, or give the equivalent in milliliters (1 tsp ≈ 5ml, 1 tbsp ≈ 15ml). Full gram conversion for tiny amounts isn't usually necessary unless precision really matters, like in professional baking.
Why do my converted metric recipes still come out different?
Beyond ingredient measurements, oven calibration, altitude, and humidity all affect baking results and aren't something a unit conversion accounts for. If a converted recipe consistently underperforms, double-check the gram weights against a reliable source and consider that oven temperature accuracy varies between US and international ovens even at the "same" converted setting.
Should I round converted measurements up or down?
For baking, round to the nearest 5g for small amounts and nearest 10g for larger ones — the difference is negligible in most recipes. For precise items like macarons or bread that depend on exact hydration ratios, keep the unrounded gram figure instead, since small variances compound in recipes that are sensitive to ratios.
What is metric baking conversion?
Metric baking conversion means changing a recipe's cup, tablespoon, and teaspoon measurements into grams and milliliters, plus converting the oven temperature from Fahrenheit to Celsius. It matters more for baking than general cooking because baking is a precise chemical process — weighing ingredients in grams removes the variability that comes from how tightly a cup of flour is packed.