Compute the coffee grounds and water for cold brew at any concentrate strength or ready-to-drink, and estimate the finished yield after the grounds absorb water.
Grounds and water are by weight (water ≈ 1 g per mL). Choose a strength and the amount you know.
Steep 12–18 h in the fridge, then strain. Dilute concentrate ~1:1 with water or milk.
About this tool
The Cold Brew Coffee Calculator sizes a batch to the strength and quantity you actually want. Pick whether you know the water you will steep or the finished drink you want to end up with, choose a strength preset, enter the amount, and the tool returns coffee grounds, water, and the estimated yield — all by weight, which is how good cold brew is measured.
Cold brew is a grounds-to-water ratio by weight (water is close to 1 g per mL). A 1:R ratio means grounds = water ÷ R. The presets cover strong concentrate (1:4), standard concentrate (1:5), a balanced brew (1:8), and ready-to-drink (1:15). Because coffee grounds soak up roughly twice their own weight in liquid, the finished yield is water minus about twice the grounds weight — so a concentrate loses more to the grounds than a weak brew. If you enter a target finished volume instead, the tool solves backward for the water and grounds needed to net that amount.
Everything is computed locally in your browser. Steep the grounds in cold or room-temperature water for about 12–18 hours in the fridge, then strain through a filter. Concentrate is typically diluted about 1:1 with water or milk over ice, while a 1:15 batch is ready to pour straight. Water units cover milliliters, liters, US cups, and fluid ounces, and the strength ratio is echoed back so you can double-check the batch.
Frequently asked questions
What is the best coffee-to-water ratio for cold brew?
For a concentrate you dilute later, 1:4 to 1:5 (grounds to water by weight) is common and strong; 1:8 gives a balanced brew, and 1:15 is ready to drink straight. Pick the preset that matches how you plan to serve it.
Why is the yield less than the water I add?
Coffee grounds absorb roughly twice their own weight in liquid and keep it when you strain, so the finished cold brew is about water minus twice the grounds weight. Stronger concentrates use more grounds, so they lose proportionally more liquid to absorption.
How long should cold brew steep?
Steep 12–18 hours. Cold or room-temperature water works; refrigerating while it steeps is safest for longer times. After steeping, strain through a fine filter or cloth to remove the grounds and stop extraction.
How do I dilute cold brew concentrate?
A 1:4 or 1:5 concentrate is usually cut about 1:1 with water or milk over ice, to taste. If you used the 1:15 ready-to-drink preset, it is already at drinking strength and needs no dilution.