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Coffee and espresso calculators

Six free tools that answer the questions a spec sheet will not: what ratio you are actually brewing, how to split a budget between machine and grinder, whether your tap water is going to scale the boiler, and whether any of it fits on the counter.

Every calculator shows its formula and its assumptions. No signup, no data leaves your browser.

Which calculator do you need?

A brew ratio is the yield in the cup divided by the dry dose in the basket. That single definition is behind half the tools here. Espresso conventionally runs 1:2, meaning an 18 g dose producing 36 g of liquid, and filter brewing runs 1:15 to 1:17. Everything else is which number you happen to be missing.

Calculator The question it answers What you enter Typical answer
Brew ratio calculator What ratio am I actually brewing, espresso or filter? Dose, yield 1:2
Espresso dose and yield What yield and time should this dose hit? Dose, basket, style 18 g to 36 g
Grinder versus machine budget How do I split a total budget between the two? Total budget 60/40 to 50/50
Water hardness and scale Will my tap water scale the machine, and how fast? Hardness, usage 50 to 100 ppm
Cost per cup What does a home shot cost against a cafe one? Bean price, dose $0.40 to $0.90
Counter space planner Will the machine and grinder physically fit? Counter run, cabinet height 24 to 40 in

Why is the budget split calculator the one to run first?

Because almost every disappointing home espresso setup is the same mistake: a machine bought at the top of the budget with whatever grinder was left over. Espresso forces water through a compressed bed of coffee in about 25 seconds at roughly 9 bar, and particle size is the only thing controlling how fast the water gets through. A grinder that cannot adjust finely enough, or that produces a wide spread of particle sizes, puts a ceiling on the machine that no feature can lift.

The budget split calculator takes a total and returns the two numbers, which is usually more grinder and less machine than people plan for. Take those figures to the machine roundup and the grinder roundup, or skip the shopping and read the three complete builds, which are already split that way.

What do the water and counter tools protect you from?

The water hardness calculator converts grains per gallon to ppm (multiply by 17.1) and estimates how quickly your machine will scale. The target window is roughly 50 to 100 ppm total hardness as CaCO3. Above about 120 ppm the right answer is treating the water rather than descaling more often, and the water guide covers how. Scale is what ends most home machines, and it is entirely preventable.

The counter space planner catches the constraint people forget, which is vertical rather than horizontal. Both the machine and the grinder are filled from the top, so a setup that slides neatly under a wall cabinet becomes unusable the first time you refill the tank. Allow 14 to 18 inches of clearance above the counter.

How accurate are these tools?

Every calculator states its formula on the page. Where a figure is a convention rather than a law, such as the 18 to 22 percent extraction yield window or the 9 bar pressure standard, the page says so. Where a result depends on a specification a manufacturer does not publish, the tool asks you for it rather than guessing. The numbers they quote are collected in the reference charts, which is the fastest place to check one without entering anything.