What is the standard fruit to sugar ratio for jam?

The standard ratio for high-pectin fruits (cooking apples, citrus, gooseberries, blackcurrants) is 1:1 by weight — equal quantities of fruit and sugar. For low-pectin fruits like strawberries, you may need slightly more sugar (1:1.1) and additional pectin for a reliable set.

What is pectin and why does it matter?

Pectin is a natural substance found in fruit that causes jam to set. Fruits high in pectin (apples, citrus peel, gooseberries) set easily. Low-pectin fruits (strawberries, cherries, rhubarb) need additional pectin or lemon juice to achieve a good set. The amount of sugar also affects setting.

Should I use jam sugar or regular sugar?

Regular granulated sugar works perfectly for high-pectin fruits. Jam sugar (which has pectin added) is useful for low-pectin fruits as it simplifies the process. Preserving sugar has larger crystals that dissolve slowly and produce less scum, but has no added pectin.

Why add lemon juice to jam?

Lemon juice adds acid, which helps pectin set properly and brightens the flavour. High-pectin fruits are naturally acidic and usually do not need extra lemon juice. Medium and low-pectin fruits benefit from 1-2 tablespoons per 500g of fruit.

Can I reduce the sugar in jam?

Reducing sugar below the standard ratio will affect the set, flavour, and shelf life of your jam. Sugar acts as a preservative. If you want less-sweet jam, use jam sugar with added pectin and follow the packet instructions, or make a reduced-sugar refrigerator jam that must be stored in the fridge and used within 2-3 weeks.

BakeCalcs

Jam Sugar Ratio Calculator

Calculate the right amount of sugar for jam based on fruit weight and pectin level.

Fruit Weight

Pectin Level

Sugar Type

How We Calculate This

This calculator applies the correct sugar ratio based on the natural pectin content of your chosen fruit. The fruit-to-sugar ratio determines both the set quality and the flavour balance of the finished jam.

Sugar Ratios by Pectin Level

High pectin: 1:1 (equal fruit and sugar)
Medium pectin: 1:1 plus lemon juice
Low pectin: 1:1.1 plus added pectin, or use jam sugar

Yield Estimate

Approximate yield = (fruit + sugar) x 0.85
15% weight loss from water evaporation during boiling

Frequently Asked Questions

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Last updated: February 2026

All calculations are based on standard ratios and conversions. Results may vary with specific ingredients, equipment, and conditions.