What is the standard ratio for Seville orange marmalade?

The classic UK ratio is 1kg Seville oranges to about 2kg sugar and roughly 2 to 2.5 litres of water (whole, unpeeled fruit weight). Delia Smith, Mary Berry and BBC Good Food all use 1kg fruit to 2kg sugar. This yields around 2.7 to 3kg of marmalade (about 6 to 7 one-pound jars). The high sugar content is essential: the finished preserve needs roughly 60% sugar for a reliable set and to keep safely. Under-sugaring risks a marmalade that will not set and will not store.

Can I use sweet oranges instead of Seville?

Yes, but sweet oranges have less pectin and acid than Seville oranges. Use a little less sugar (around 1.7x the whole-fruit weight) and add the juice of 2 lemons per kg of sweet oranges for pectin and acid to help it set. The flavour will be milder and sweeter. Note this calculator works from raw whole-fruit weight, not cooked pulp.

When are Seville oranges available?

Seville oranges have a very short UK season, typically January to mid-February. Buy them when you see them and freeze whole if you cannot make marmalade straight away. They freeze perfectly and can be used from frozen.

Why does marmalade need so much water?

The water is needed to soften the citrus peel before the sugar is added. The fruit simmers in water for 1.5-2 hours to make the peel tender. Most of this water evaporates during the subsequent boiling with sugar, which is why the final yield is much less than the total starting volume.

How do I know when marmalade has reached setting point?

The setting point is 105C. Test by placing a teaspoon of marmalade on a cold saucer, letting it cool for a minute, then pushing it with your finger. If it wrinkles, it has reached setting point. Always remove the pan from the heat while testing to avoid over-cooking.

Marmalade Calculator — Free Online Tool

How We Calculate This

This calculator uses traditional UK marmalade ratios on a whole-fruit basis (weigh the washed, unpeeled fruit). The classic Seville orange marmalade uses roughly a 1:2:2 ratio of fruit:sugar:water (kg sugar and litres of water per kg of fruit) — the ratio used by Delia Smith, Mary Berry and BBC Good Food.

Standard Ratios (per 1kg whole fruit)

Seville oranges: 2kg sugar, ~2L water
Sweet oranges: 1.7kg sugar, ~2L water + juice of 2 lemons (for pectin and acid)
Lemons / limes: 2kg sugar, ~2.3L water

The high sugar level is a food-safety requirement, not just for sweetness: a properly set marmalade is about 60% sugar, which is what makes it keep. Don't reduce the sugar below these ratios. Boil to a setting point of 105°C (test with a cold-saucer wrinkle test).

Yield

Estimated yield ≈ fruit weight × 2.8 (about 2.7 to 3kg per kg of fruit)
Most of the added water evaporates during cooking
Jar count based on 454ml (1lb) jars at 1.3g/ml density

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.