AGITATIVE

Caffeine Estimate Calculator

Enter your dry coffee dose to get a rough caffeine estimate and range — a planning tool, not a lab reading.

A typical drip cup uses ~10g; a double espresso shot uses ~18g.
~10mg/g is a commonly cited average for roasted arabica; robusta runs higher.

Estimated caffeine

Estimate
100 mg
Likely range
80–120 mg

Where the estimate comes from

This tool multiplies your dry-coffee dose by a commonly cited average of about 10 milligrams of caffeine per gram of roasted coffee. That figure roughly matches widely referenced numbers like ~95mg in an 8oz cup brewed with about 10g of grounds, and ~150-200mg in an 18g double-espresso dose.

Because caffeine content genuinely varies by bean and roast, the tool also shows a ±20% range around the estimate rather than presenting a single number as exact. Treat it as a starting point for comparing brews, not as a substitute for product labeling.

Frequently Asked Questions

Does the brew method change how much caffeine ends up in the cup?

Less than most people assume. Caffeine is highly water-soluble and extracts efficiently across nearly every home brewing method within normal contact times, so the biggest driver of total caffeine is simply how much dry coffee you used — not whether you brewed espresso, drip, or French press.

Why does a small espresso shot compare to a bigger drip cup?

An espresso shot is concentrated into a small volume but typically uses a smaller dose of coffee (roughly 18g for a double shot) than a large drip cup might. Caffeine tracks the dose in grams, not the serving size in millilitres, which is why a strong-tasting shot and a milder mug can land in a similar caffeine range.

Why does this tool give a range instead of one number?

Bean species (arabica vs. robusta), origin, roast level, and even the specific harvest all shift caffeine content in the raw bean, typically across roughly a 1.1%-2.2% dry-weight range. A single average can't capture that spread, so the range communicates realistic uncertainty rather than false precision.

Is this a medical or health tool?

No. This is a rough planning estimate for people curious about their brew, not a laboratory measurement or medical guidance. If caffeine intake matters for your health, check product packaging or ask a healthcare professional rather than relying on an estimate.

Estimate only, not medical or nutritional advice. Actual caffeine varies by bean, roast, and brewing time.