Rex says
Everyday utility math — the kind you'd otherwise pull up four browser tabs for. I keep it to one clean answer.
Try a scenario
Click to load — tweak from there.Inputs
Result
Coffee dose (g)
35.7
Brew water (g)
571
Absorbed by grounds (g)
71
Approx. tablespoons
6.7
Psst — share this and help Rex grow
One click, a permanent link with your numbers baked in.
How to use this
- 1Enter finished coffee (g (ml)).
- 2Enter water : coffee ratio.
- 3Read your coffee dose (g) on the right — it updates as you type.
- 4Hit Share to keep the scenario or send it to someone.
About this calculator
Dial in a repeatable cup. Pick your brew ratio and the finished volume you want, and get the coffee dose, total brew water, and the extra water absorbed by the grounds.
Worked example
Using the values the calculator loads with:
Inputs
- Finished coffee: 500 g (ml)
- Water : coffee ratio: 16
Results
- Coffee dose (g): 35.7
- Brew water (g): 571
- Absorbed by grounds (g): 71
- Approx. tablespoons: 6.7
What each field means
Inputs
- Finished coffee (g (ml))
- The finished coffee used in the calculation, measured in g (ml). Starts at 500 g (ml) so you have a working example on load.
- Water : coffee ratio
- The water : coffee ratio used in the calculation. Starts at 16 so you have a working example on load. Accepted range: 8–20.
Results
- Coffee dose (g)
- Returned as a decimal number and shown as the headline result. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
- Brew water (g)
- Returned as a decimal number. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
- Absorbed by grounds (g)
- Returned as a decimal number. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
- Approx. tablespoons
- Returned as a decimal number. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
FAQ
What ratio should I start with?
1:16 is the common pour-over starting point. Go lower (1:14) for a heavier cup, higher (1:17–18) for a lighter one.
Why is brew water more than my cup size?
Wet grounds hold roughly twice their weight in water, so you always pour more than you pour out.
Accuracy and limitations
- Estimates assume standard, average conditions — local rules, pricing, and materials vary.
- Results are rounded for readability; add a buffer before ordering, booking, or committing.
- Double-check anything with a real cost attached against a local quote.
Cite this calculator
Writing about this topic? Grab a citation — every link helps keep these tools free.
RevenueLab. (2026). Coffee Brew Ratio Calculator. Retrieved from https://www.revenuelab.fyi/toolbox/coffee-ratio
<p>Source: <a href="https://www.revenuelab.fyi/toolbox/coffee-ratio" target="_blank" rel="noopener">Coffee Brew Ratio Calculator — RevenueLab</a> (2026).</p>
Source: [Coffee Brew Ratio Calculator — RevenueLab](https://www.revenuelab.fyi/toolbox/coffee-ratio) (2026).