Caffeine estimate methodology

The caffeine estimator gives a range, not a single number, because caffeine content genuinely varies by bean, roast, grind, brew time and technique — even between two cups made the same way. Nothing on CoffeeHQ measures the caffeine in your actual cup; every figure is a calculated estimate.

The calculation

Total caffeine extracted from the coffee grounds is approximated as the dose (in grams) multiplied by a per-method milligram-per-gram coefficient range:

• Espresso: 3.3-4.4mg per gram of dose
• Filter or immersion methods: 5.3-6.7mg per gram of dose
• Cold brew concentrate: 6.0-8.5mg per gram of dose

That total is then divided across the total brewed volume and sampled by your serving size — so a smaller serving from a larger batch gets a proportionally smaller estimate. These coefficients were calibrated to stay consistent with the caffeine ranges already published on individual drink pages, rather than treated as an independent, unrelated figure.

Species and decaf adjustments

Robusta is commonly reported as higher in caffeine than arabica; when you specify robusta, the estimate applies an approximate 1.3-1.8x multiplier. This is a documented approximation, not a precise figure — real variation between cultivars and lots is wider than any single multiplier can capture. Decaf coffee is never treated as caffeine-free: regulatory decaffeination typically removes at least 97% of the original caffeine, not 100%, so decaf estimates use a small non-zero range (2-15mg per serving) rather than zero.

What this is not

This estimator is not medical advice. It does not know your personal caffeine tolerance, does not account for medication interactions, and makes no claim about what's safe during pregnancy or for any health condition. If caffeine intake matters for your health, speak to a healthcare professional rather than relying on this or any online estimate.