How Much Caffeine Is Left? Dose by Hour Chart

Written and maintained by cisyWang

Last updated: September 24, 2026

Find your dose and the hours since you drank it

This page answers one narrow question: given a specific amount of caffeine and a number of hours, how much is still expected to be in your system? Because the share remaining depends only on elapsed time, the chart below works for any dose you find on a can, a label, or a menu.

A single dose behaves like this under a five-hour half-life: about 50% is left at 5 hours, 25% at 10 hours, 12.5% at 15 hours, and roughly 4% at 24 hours. The table applies those shares to five common doses.

Hours later	50 mg	95 mg	150 mg	200 mg	400 mg
1 h	44 mg	83 mg	131 mg	174 mg	348 mg
2 h	38 mg	72 mg	114 mg	152 mg	303 mg
3 h	33 mg	63 mg	99 mg	132 mg	264 mg
4 h	29 mg	55 mg	86 mg	115 mg	230 mg
5 h	25 mg	48 mg	75 mg	100 mg	200 mg
6 h	22 mg	41 mg	65 mg	87 mg	174 mg
8 h	16 mg	31 mg	49 mg	66 mg	132 mg
10 h	13 mg	24 mg	38 mg	50 mg	100 mg
12 h	9 mg	18 mg	28 mg	38 mg	76 mg
15 h	6 mg	12 mg	19 mg	25 mg	50 mg
18 h	4 mg	8 mg	12 mg	16 mg	33 mg
24 h	2 mg	3 mg	5 mg	7 mg	14 mg

Amounts are rounded, and every row assumes one dose with no additional caffeine logged afterwards. Two drinks in a day do not share a row in this table; each one decays on its own clock and the results are added at the end, which is what the calculator does.

If your dose is not in the chart

The remaining amount is proportional to the dose, so the chart scales. Take the share for the hours you care about and multiply it by your own number: 5 hours means half, 10 hours means a quarter, 15 hours means an eighth.

A worked example with 69 mg, a figure that appears on quite a few energy drinks and supplement labels:

2 hours later: about 52 mg, roughly three quarters of the dose.
5 hours later: about 34.5 mg, exactly half.
10 hours later: about 17 mg, roughly a quarter.
15 hours later: about 9 mg, roughly an eighth.
20 hours later: about 4 mg.

How long the dose matters depends on the threshold rather than on the dose disappearing. The same 69 mg falls below 25 mg in about 7 hours 19 minutes and below 5 mg in about 18 hours 56 minutes.

Fast, average, and slow metabolism, compared

The chart above uses the five-hour default. Reported averages for healthy adults run from roughly three to seven hours, so thefactors guide explains what shifts them and the calculator lets you switch between three presets. This is what a single 200 mg dose looks like on each one.

Model	4 hours later	8 hours later	12 hours later
Fast metabolism (4 h half-life)	100 mg	50 mg	25 mg
Average metabolism (5 h half-life)	115 mg	66 mg	38 mg
Slow metabolism (7 h half-life)	135 mg	91 mg	61 mg

The same 200 mg dose takes 12 hours to fall below 25 mg on a four-hour half-life, 15 hours on the five-hour default, and 21 hours on a seven-hour half-life. That spread is the reason a slow metabolizer can finish the same afternoon coffee and still be well above a bedtime target hours after a fast metabolizer has cleared it.

How long until a dose is effectively gone?

Caffeine never formally reaches zero on an exponential curve, so the useful question is when it crosses a threshold. Two thresholds matter on this site: the 25 mg bedtime planning target and the 5 mg clearance estimate.

Dose	Below 25 mg	Below 5 mg
50 mg	5 h	16 h 37 m
95 mg	9 h 38 m	21 h 14 m
150 mg	12 h 55 m	24 h 32 m
200 mg	15 h	26 h 37 m
400 mg	20 h	31 h 37 m

Both thresholds are planning values created for this tool, not clinical limits. Sleeping well is not guaranteed by landing under either one, which is why the disclaimer keeps that distinction explicit.

How this differs from the bedtime estimate

This page is a lookup table for one dose at a time. The bedtime estimate answers a different question: what several drinks, taken at different hours, add up to at the specific time you plan to sleep. If you want a single number for your own day rather than a chart to read, start with the calculator.

Common questions

How much caffeine is left after 6 hours?

Under a five-hour half-life, about 44% of a dose is still present six hours later. That works out to roughly 41 mg from a 95 mg coffee, 65 mg from a 150 mg pre-workout, and 174 mg from a 400 mg dose.

How long does 100 mg of caffeine last?

Under a five-hour half-life, 100 mg falls below 25 mg in about 10 hours and below 5 mg in about 22 hours. The amount keeps halving after that without formally reaching zero, so how long it lasts depends on the threshold you choose.

Is 69 mg of caffeine a lot?

It sits between a single espresso (about 63 mg) and an 8 oz brewed coffee (about 95 mg), so it is a moderate single dose. Timing usually matters more than the number for sleep: 69 mg at 15:00 leaves about 23 mg at a 23:00 bedtime, while the same 69 mg at 20:00 leaves about 46 mg.

Does the chart change with the fast or slow setting?

Yes, and by more than most people expect. A 200 mg dose is about 25 mg after 12 hours on a four-hour half-life, but about 61 mg after 12 hours on a seven-hour half-life. Switching the preset in the calculator is the fastest way to see the range for your own day.

Do I add these numbers up across several drinks?

Yes. Each dose decays independently, so you decay each one by its own elapsed time and then add the remainders. Three drinks logged two hours apart do not stay at the single-dose figure, which is why the calculator sums every entry instead of averaging the day.

Run your own numbers

The CaffCutoff calculator turns these ideas into an estimate for your own day: add each drink, set a target bedtime, and read the remaining caffeine, the cutoff estimate, and the decay timeline.