Simple Syrup Ratio Calculator
Work out exactly how much sugar and water to combine for a batch of simple or rich syrup, in cups, ounces or millilitres, plus the sugar weight in grams.
How it works
Water = volume ÷ (1 + ratio × 0.625) · Sugar = ratio × water · (ratio = sugar parts per 1 part water)
Simple syrup is sugar dissolved in water. Dissolved sugar does not vanish — it adds roughly 62.5% of its dry volume back as liquid, so a 1:1 batch of one cup sugar and one cup water yields about 1.6 cups of syrup, not two. Working backwards from the finished volume you actually need avoids ending up with far more or less than the recipe called for. Rich (2:1) syrup packs more sugar per spoonful, so cocktails need less of it and it resists spoiling longer in the fridge.
Worked example
You want 2 cups of simple (1:1) syrup. Water = 2 ÷ (1 + 1 × 0.625) = 2 ÷ 1.625 = 1.23 cups; sugar = 1 × 1.23 = 1.23 cups (about 246 g). Combine, warm until the sugar dissolves, and you land near 2 cups of finished syrup.
Frequently asked questions
What is the difference between simple and rich syrup?
Simple syrup is equal parts sugar and water (1:1); rich syrup is two parts sugar to one part water (2:1). Rich syrup is sweeter and thicker, so you use less of it in a drink, and its higher sugar concentration helps it keep for several weeks refrigerated versus about two weeks for 1:1.
Do I need to boil simple syrup?
No. Gentle heat just speeds up dissolving. You can also shake equal parts sugar and room-temperature water in a sealed jar until the sugar disappears — no heat needed for 1:1. Rich (2:1) syrup dissolves more reliably with a little warmth.
How long does simple syrup last?
Refrigerated in a clean sealed jar, 1:1 syrup keeps about two weeks and 2:1 syrup about a month. A tablespoon of vodka or a splash of citric acid extends shelf life. Discard it if you see cloudiness or floating specks.
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This calculator is for educational purposes. Double-check important results before acting on them.