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Both calculators run independently — change the inputs on either side to compare results.

Caffeine Sleep Impact Calculator

Calculate how many milligrams of caffeine remain active in your system at bedtime based on when and how much you consumed, using a standard 5-hour half-life. Even moderate residual caffeine at bedtime measurably disrupts sleep architecture, not just sleep onset.

Caffeine Consumption Time (hours (24h format))

Caffeine Amount (mg)

Desired Bedtime (hours (24h format))

Fill in the required fields to see your result.

Sleep

Sleep Efficiency Calculator

Measure what percentage of your time in bed is actually spent sleeping — a key clinical marker of sleep quality used in insomnia diagnosis and treatment. Efficiency above 85% indicates healthy sleep; under 80% suggests insomnia or fragmented sleep that warrants investigation.

Time Actually Asleep (hours)

Time Spent in Bed (hours)

Fill in the required fields to see your result.

Key differences

	Caffeine Sleep Impact Calculator	Sleep Efficiency Calculator
Category	Sleep	Sleep
Inputs required	3	2
Result	Caffeine Remaining at Bedtime (mg)	Sleep Efficiency (%)
What it does	Calculate how many milligrams of caffeine remain active in your system at bedtime based on when and how much you consumed, using a standard 5-hour half-life. Even moderate residual caffeine at bedtime measurably disrupts sleep architecture, not just sleep onset.	Measure what percentage of your time in bed is actually spent sleeping — a key clinical marker of sleep quality used in insomnia diagnosis and treatment. Efficiency above 85% indicates healthy sleep; under 80% suggests insomnia or fragmented sleep that warrants investigation.