Coffee Ratio Calculator & Recipe Scaler
A ratio only tells you how much water to boil. This calculator scales the whole recipe: pick a named technique like the Hoffmann V60 or Tetsu Kasuya's 4:6 method, set your dose, water, or cups, and every pour target in the schedule is recalculated. Or build your own recipe from a method, ratio, and pour count.
How scaling works
Water scales linearly: doubling the dose doubles every cumulative pour target. Timings do not scale, because a deeper bed of coffee drains slower, not proportionally slower. Rather than invent fake stage times, the calculator keeps the original schedule and tells you when to expect a longer drawdown and to compensate with a slightly coarser grind.
Espresso works in dose and yield instead of brew water. A 1:2 shot from 18 g lands at 36 g in the cup; scale the dose and the target yield follows. Shot time stays a grind problem, and the calculator says so instead of pretending otherwise.
Recipe quoted in grams per litre instead of a 1:x ratio? The ratio converter turns 60 g/L into 1:16.7 and a dose for your batch size.
Every recipe here has a full guide with technique notes on the recipes page. For the theory behind ratios and strength, see how coffee extraction works and how grind size changes the cup. To brew a scaled recipe with a guided timer, use the BeanBench app; it has these recipes built in.