Coffee Calculator

How Much Coffee Should You Drink?

This coffee calculator estimates a personal caffeine target from body weight and sensitivity, then compares your chosen drink and serving count against that target and the common 400 mg daily guideline. Related tools: Caffeine Half-Life Tracker and Coffee Kick Calculator.

Caffeine Formula

$$\text{Caffeine target (mg)} = \text{body weight (kg)} \times \text{sensitivity factor}$$

Typical sensitivity factors range from 3 mg/kg for very sensitive people to 8 mg/kg for very tolerant people. Divide your target by the caffeine in one serving to estimate how many portions fit your plan.

Example

A 70 kg person with average sensitivity (6 mg/kg) has a target of 420 mg. One 8 oz brewed coffee at 95 mg means about 4.4 cups would reach that personal target, though most guidelines still cap daily intake near 400 mg.