This is a general formula for a coffee to water ratio and the ratios for three popular brewing methods: pour-over/drip coffee ratio, French press, and cold brew coffee ratio.

The calculator predicts the level of alertness and shows it as a cool visual graph, depending on the time you’ve slept and the dose of caffeine you’ve ingested.

The calculator predicts the caffeine effect on the level of alertness and shows it as a cool visual graph, depending on the time you’ve slept and the dose of caffeine you’ve ingested.