Coffee Calculator — Grounds, Water & Brew Guide

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How this is calculated

Every brewing method works at a different water-to-coffee ratio (by weight). The Specialty Coffee Association recommends roughly 15 g of water per 1 g of coffee for drip and pour-over styles; French press is slightly richer at 14:1 for a fuller body; AeroPress is more concentrated at 12:1. Cold brew uses an 8:1 ratio but steeps for 12+ hours in cold water to extract slowly — the result is usually a concentrate diluted 1:1 before drinking. Espresso is the most extreme at 2:1: 30 ml of hot water is forced through roughly 15 g of finely-ground coffee under ~9 bar of pressure in 25–30 seconds.

The strength multiplier adjusts the dose within the chosen method: mild brews use 80% of the baseline dose, medium uses the standard, and strong uses 125%. Cup sizes are fixed at 240 ml for drip-style methods and 30 ml per espresso shot. Caffeine is estimated at approximately 10 mg per gram of dry coffee — this is a broad average that varies with variety (Robusta has roughly double the caffeine of Arabica), roast darkness, and grind fineness.

Weighing grounds on a kitchen scale gives far more consistent results than volume scoops, since grind size and bean density can shift a tablespoon between 5 g and 10 g. Water temperature (90–96 °C / 195–205 °F), freshness of the beans, and the evenness of the grind are equally important variables not captured by the ratio alone.