To halve a recipe, multiply every explicit ingredient quantity by exactly 1/2. That turns 3/4 cup into 3/8 cup, 1 1/2 teaspoons into 3/4 teaspoon, and 3 eggs into 1 1/2 eggs. Keep those fractional results exact; do not apply the factor automatically to equipment, cooking time, temperature, doneness, storage, or food-safety decisions.

Multiply fractions before converting them

Treat each amount as an exact fraction. Three-quarters multiplied by one-half is three-eighths; one and one-half is 3/2, and 3/2 × 1/2 becomes 3/4. This approach is clearer than turning every value into a short decimal first. A decimal such as 0.33 may already have lost the difference between one-third and a rounded estimate. Enter the quantity separately from “cup flour” or “teaspoons vanilla” so the arithmetic cannot change the wording. Copy the exact fraction, then choose a measuring tool that can represent it sensibly.

How to halve a recipe that calls for 3 eggs

The arithmetic answer is 3 × 1/2 = 3/2 = 1 1/2 eggs. One way to represent the half is one whole egg plus half of a second: beat the second egg until yolk and white are uniform, weigh its contents without the shell, and use half of that measured mass. The same mass method represents half of one egg when the original recipe calls for only one. Do not round 1 1/2 to one or two eggs; either choice changes the intended egg quantity by one third. Egg sizes vary, and yolk and white can play different structural roles, so an assumed spoon volume or only one component is not equivalent to half of that whole egg. This step measures quantity only; follow the trusted recipe and authoritative guidance for handling and cooking.

Keep temperature and time outside the factor

Halving ingredient quantities does not mean halving oven temperature. It also does not provide a universal cooking-time formula. A shallower layer, smaller pan, different material, or fewer pieces can change heat transfer in different ways. Keep the original temperature unless the trusted recipe or appliance guidance says otherwise, choose a suitable vessel, and begin checking doneness according to the method's visual or measured cues. For food that requires a safe internal temperature, follow authoritative safety guidance. The quantity result is useful preparation, not a replacement for the method.