---
title: "Sleep Duration Calculator | Numequo"
description: "Calculate the elapsed time between bedtime and wake-up, including overnight sleep. Includes the formula and practical examples."
canonical: "https://www.numequo.com/health/sleep-recovery/sleep-duration-calculator/"
locale: "en"
---
[Numequo](https://www.numequo.com/) › [Health](https://www.numequo.com/health/) › [Sleep and recovery](https://www.numequo.com/health/sleep-recovery/)

# Sleep Duration Calculator

Enter bedtime and wake-up time to measure the time interval. This calculates time in bed, not sleep quality.

## Input data

- **Bedtime** - type: time; default: 23:00
- **Wake-up time** - type: time; default: 07:00

## How it works

Duration = wake-up time − bedtime. When wake-up is earlier on the clock, it is treated as occurring the following day.

> This estimate is educational and is not medical advice.

## Quick examples

- **11:00 PM → 7:00 AM** - Bedtime: 23:00, Wake-up time: 07:00
- **10:30 PM → 6:15 AM** - Bedtime: 22:30, Wake-up time: 06:15
- **1:00 PM → 2:30 PM** - Bedtime: 13:00, Wake-up time: 14:30

## Understanding your result

The result measures the scheduled interval between the two times. Time needed to fall asleep and periods awake during the night are not subtracted, so actual sleep may be shorter.

Last verified: 29 September 2026 (2026-09-29)

## Sources

- <a href="https://www.cdc.gov/sleep/about/index.html" rel="nofollow">CDC sleep information</a>

## Frequently asked questions

### Does the calculator handle sleep across midnight?

Yes. A wake-up time earlier than bedtime is automatically treated as the following day.

### Is time in bed the same as sleep duration?

Not always. Falling asleep and waking during the night can make actual sleep shorter.

### Does this assess sleep quality?

No. It calculates a clock interval only.

### Can I use it for a daytime nap?

Yes. Enter a wake-up time later than the nap start time.

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- [Protein Needs Calculator](https://www.numequo.com/health/nutrition-energy/protein-needs-calculator/) - Estimate the EFSA population reference intake for protein from body weight and life stage.
- [BMI Calculator](https://www.numequo.com/health/body-metrics/bmi-calculator/) - Estimate adult body mass index in metric or imperial units.
- [Time Duration Calculator](https://www.numequo.com/time/durations-schedules/duration-calculator/) - Find the elapsed time between two clock times.
- [Ideal Weight Calculator](https://www.numequo.com/health/body-metrics/ideal-weight-calculator/) - Compare four common height-based reference formulas.

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