Everyday planning
Adjust ingredient quantities for a new number of servings, keeping the same portion size.
Recipe scaling factor
Enter the servings and ingredients, then select Scale recipe.
| Ingredient | Exact quantity | Decimal quantity |
|---|
Calculated in your browser. This changes ingredient quantities only; cooking time, temperature, pan size, and cooking method are not adjusted.
Keep the portion size the same and enter 4 original servings and 6 target servings. The factor is 6 ÷ 4 = 3/2, so each original amount increases by half. This illustrative ingredient list shows the arithmetic, rather than a tested recipe.
| Ingredient | For 4 servings | For 6 servings |
|---|---|---|
| Flour | 2 cups | 3 cups |
| Sugar | 1/2 cup | 3/4 cup |
| Milk | 250 mL | 375 mL |
| Eggs | 1 | 1 1/2 |
The egg quantity is 1 1/2, or 1.5000 at four decimal places. These are the same amount. The tool does not round it to one or two eggs; that would change the ingredient's proportion. Use your recipe's method to decide how to measure it.
Milk becomes 375 mL, while flour becomes 3 cups. Each row keeps its own unit label. The calculator neither adds these quantities together nor converts flour volume into weight.
1 × (1 ÷ 3) = 1/3
The exact quantity stays 1/3 cup. A four-place decimal display is ≈ 0.3333 cup. Changing the decimal places does not change the exact fraction.
After a successful calculation, use Copy link to share a short recipe or Save inputs file to download its conditions. Both preserve the original and target servings, ingredient names, amounts, units, and decimal-place setting. Large recipes can exceed the link-length limit; when that happens, save a file instead. No ingredients are removed or shortened to make a link fit.
Open a shared link or use Load inputs file beside the input heading to restore the complete recipe from a CalculateSite JSON file (up to 64 KiB). Review the values, then select Scale recipe. Loading inputs does not calculate a result or add a recent calculation. A rejected file leaves your current inputs in place.
Making ten servings next time? Load the saved four-to-six-serving example, keep the original servings at 4 and the original flour at 2 cups, then change only the target to 10. The new factor is 10 ÷ 4 = 5/2, giving 5 cups of flour. The file saves the original inputs, so do not replace the flour with the previous 3-cup result while leaving the original yield at 4; that would scale it twice.
Files are plain text that anyone receiving them can read. Links also contain readable input values; neither method encrypts a recipe or lets you revoke copies already shared. File loading and calculation happen in your browser, without uploading your ingredients to our server. See our privacy policy for how calculation links and saved inputs are handled.
The scaling factor is target servings ÷ original servings. For every ingredient, new amount = original amount × scaling factor. This is the yield-adjustment method described in Western Kentucky University's restaurant-management course notes.
Original and target servings must be greater than zero and no more than 1,000, with up to 10 decimal places. A target of 0.5 means half of one original-sized serving. For example, moving from 4 servings to 0.5 uses a factor of 1/8. Serving inputs use decimal notation, rather than fractions.
Enter 1–20 ingredient rows. Each amount can be a whole number, a plain decimal, a simple fraction, or a mixed number. Decimals allow up to 15 digits before the decimal point and 10 after it. Fractions allow up to 15 digits in each numerator and denominator; a mixed number also allows 15 digits in its whole-number part. Every numeric input is limited to 64 characters.
Use 1/2 instead of ½, and 1 1/2 instead of 1½. The denominator must be positive. A mixed number's fractional part must be less than one, so use 2 1/2 or 5/2 instead of 1 3/2. Optional leading + signs are accepted; minus signs, commas in ingredient amounts, scientific notation, and units within the amount are not.
Quantities and the serving ratio are stored as exact fractions. The decimal view is rounded directly from those fractions using integer remainders. Choose 0, 2, 4, 6, or 10 decimal places, with 4 as the default. Exact halfway values round up, and ≈ marks a rounded decimal. An exact fraction never changes when you change display precision.
This arithmetic keeps ingredient proportions, but it is not a complete cooking adjustment. For practical considerations when changing batch size, see Escoffier's guide to scaling recipes. Cooking time, oven temperature, equipment, and pan dimensions are not automatically multiplied by the serving factor.
No. The unit field is a label that stays with its ingredient. The calculator does not convert between volume units, between mass units, or between volume and mass. It also does not interpret a unit's regional definition. Enter the original recipe's unit and keep its meaning consistent.
Yes. Enter 0.5 as the target servings. Both serving counts must be positive and at most 1,000. The portion size stays the same; only the number of portions changes. To halve a recipe that makes 4 servings, use a target of 2 instead.
Put a space between the whole number and the fraction, such as 1 1/2. This means 1 + 1/2, or 1.5. The fraction must be less than 1. A simple improper fraction such as 3/2 is also accepted and gives the same amount. Use keyboard digits and a slash, not a single-character fraction symbol.
The result remains the exact proportional quantity. It is not rounded automatically to a whole item or a practical measuring increment. Decide how to measure or adjust that ingredient using the recipe's method; rounding a quantity changes its proportion.
Every included row requires a numeric amount. Remove a row you do not want to scale. You can enter 0 when the original quantity is actually zero, but “to taste” is not a numerical zero and cannot be scaled by this tool. Ingredient names and units may be left blank.
No. This calculator scales ingredient quantities only. The serving factor is not applied to temperature, time, pan size, or cooking method. Follow the recipe's guidance and account for the equipment and batch size separately.
No automatic conversions, spelling changes, or singular/plural changes are made. Leading and trailing spaces are removed, but the labels otherwise stay as entered. A blank ingredient name receives a numbered label so you can still identify its row.
Ingredient names, units, and amounts all contribute to the encoded URL's length. Some characters need extra space in a URL. When the complete link exceeds our limit, use Save inputs file to keep the full recipe. The recipient can load that file on this page and review the inputs before scaling.