Time Converter
Durations across every scale.
Runs on your device
At a glance
- Processing:
- Runs locally in your browser
- Privacy:
- Your files stay on your device — nothing is uploaded to a server
About this tool
Convert milliseconds up to years (using 365.25-day average years and 30.44-day months, disclosed in the tool). Good for billing, project estimates and study planning.
How to use it
- Enter the duration.
- Choose source and target units.
- See the exact breakdown.
Good to know
- Months and years are averages (month = 30.4375 days, year = 365.25 days) — not calendar-exact for specific date ranges. Use the Date Calculator for calendar math.
Frequently asked questions
How do I convert durations?
Enter a value, pick the source and target units, and read the result instantly. For example: 1.5 hours = 90 minutes. All math runs locally in your browser.
Is my data uploaded or stored?
No. Unit conversion is pure arithmetic in your browser — nothing is sent, uploaded or stored.
How precise are the results?
Conversions use double-precision factors and display up to 6 significant decimals with trailing zeros stripped, so everyday and technical values both stay accurate.