Health Tool ยท ๐Ÿ˜ด

Sleep Calculator

Find the best bedtime based on 90-minute sleep cycles and your wake-up time. Free, instant, no sign-up.

๐Ÿ“– Read the complete Sleep Calculator guide โ†’

Related Calculators

๐Ÿ”’ All calculations happen in your browser. No data is sent to any server. No sign-up required.
Go to Sleep at...

Formula

Bedtime = Wake time โˆ’ (Cycles ร— 90 min) โˆ’ 14 min

Example

Wake at 7:00am โ†’ Sleep at 9:46pm (6 cycles) or 11:16pm (5 cycles)

Frequently Asked Questions

Why do I feel groggy after 8 hours?

You likely woke mid-cycle. Waking at cycle completion feels natural and refreshed.

How many cycles do I need?

5-6 cycles (7.5-9 hours) is ideal for most adults.

Does snooze help?

No โ€” it starts a new cycle and interrupts it 9 minutes later, causing more grogginess.

๐• Share ๐Ÿ’ฌ WhatsApp this.textContent=\'๐Ÿ”— Copy Link\',2000);return false' style='background:#1a1a2e;border:1px solid rgba(108,99,255,0.2);color:#a0a0c0;padding:8px 16px;border-radius:8px;font-size:12px;text-decoration:none;cursor:pointer'>๐Ÿ”— Copy Link
๐Ÿ”— Embed This Calculator on Your Website
Add this calculator to your blog or website for free. Just copy and paste:
<iframe src="https://calchubpro.netlify.app/calculators/sleep.html" width="100%" height="500" frameborder="0" style="border-radius:12px;border:1px solid #6c63ff22" title="Sleep โ€” CalcHub Pro"></iframe>