Halving looks simple until a recipe contains three-quarters of a cup, one and one-half teaspoons, or a single egg. The serving factor is still exactly 1/2, but the result should remain readable and the practical cooking decision should stay visible. RecipeScale calculates explicit quantities; it does not turn a mathematical fraction into advice about technique, equipment, or doneness.

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.

Treat half an egg as a measurement problem

If the original recipe uses one egg, the exact halved quantity is one-half egg. The calculator should show that truth instead of rounding to zero or one. In the kitchen, one option is to beat the egg until uniform and weigh the portion required, using the recipe author's guidance where available. Another is to choose a batch size that produces a whole egg. Yolks and whites can have different structural roles, so do not assume that discarding either part preserves the recipe. Record the practical decision in your own notes; RecipeScale does not make it automatically.

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.