How much caffeine is in that?

Caffeine content varies more within a category than between them — an espresso can have less than a mug of filter coffee.

The caffeine Unit

Almost exactly a filter coffee, mug

95 mg is more than 6 of the 10 references on this page.

Reference figures are measurements and are rounded; the unit conversion behind them is exact.

Every reference on this page, with its size and its ratio to your number
Reference	Size	Yours ÷ theirs	Note
decaf coffee	3 mg	31.7×	3 mg
green tea	28 mg	3.39×
cola	34 mg	2.79×
black tea	47 mg	2.02×
espresso shot	63 mg	1.51×
energy drink, 250 ml	80 mg	1.19×
filter coffee, mug	95 mg	1×
large takeaway coffee	175 mg	0.543×
single-dose caution level	200 mg	0.475×
daily limit for adults	400 mg	0.238×	EFSA guidance

A shot of espresso has about 63 mg of caffeine and a mug of filter coffee about 95 — the small strong drink is the weaker dose.
European food safety guidance puts 400 mg a day and 200 mg in one sitting as the thresholds for healthy adults.

Frequently asked

400 mg a day is the usual guidance for healthy adults — about four mugs of filter coffee. Pregnancy guidance is half that.

Per millilitre, far more. Per serving, less: a 30 ml espresso has 63 mg and a 240 ml mug of filter has 95.

Caffeine content varies widely with bean, grind, brew time and serving size; these are typical values.