Time Duration Converter Free Online
Convert between time and duration units instantly. Supports microseconds, milliseconds, seconds, minutes, hours, days, weeks, months, and years. Useful for video timing, server uptime, project planning, and scientific work.
All Conversions
Pro — bulk batch conversion, API access, history & favorites
API access · Priority queue · Team workspace
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How It Works
Enter a Value
Type the number you want to convert into the From input. The conversion runs as you type — no Convert button needed. Decimals and very small or very large numbers are supported via scientific notation.
Pick Source & Target Units
Use the two dropdowns to choose source (From) and destination (To) units. The result updates automatically. Use the swap button to flip the conversion direction in one click.
See All Conversions
Below the main result, the All Conversions panel shows your input value converted into every supported unit at once — perfect for comparing metric vs imperial side by side.
Time Duration Converter Features
Sub-second Precision
Microsecond (μs = 1e-6 s) and millisecond (ms = 0.001 s) for performance benchmarking, audio buffer sizing, and scientific timing.
Everyday Units
Second, minute, hour are the SI base and derived units. 1 hour = 3600 s exactly.
Calendar Units
Day = 86,400 s exactly. Month is computed as 30 days, year as 365 days (non-leap). For exact calendar diffs across leap years, use a date difference tool.
Long Durations
Convert project years to weeks, server uptime in days to seconds, or geological hours to years.
Live Conversion
All conversions run on every keystroke. Use swap to invert without retyping.
100% Private
All math runs in your browser. No tracking, safe for confidential project timelines or system metrics.
Free vs Pro
| Feature | Free | Pro |
|---|---|---|
| All 9 time duration units | ||
| Live conversion | ||
| All-units result table | ||
| Bulk CSV / Excel conversion | — | |
| REST API access | — | |
| Custom precision settings | — |
Frequently Asked Questions
The Julian year (365.25 d) and Gregorian year (365.2425 d) are calendar averages. We use a flat 365 days for simplicity — it matches how most people think about a year. For precise calendar arithmetic across leap years, use a date difference tool.
Calendar months are 28–31 days. We use 30 days as the standard average for unit conversion. If you need an exact month between specific dates, convert via days first using a date diff tool.
Using 365 days: 31,536,000 seconds. Using 365.25 days (astronomical): 31,557,600 seconds. The difference is 86,400 s — exactly one day.
Microsecond (μs) = 10⁻⁶ s, nanosecond (ns) = 10⁻⁹ s, picosecond (ps) = 10⁻¹² s. We support down to μs; for ns/ps divide μs by 1000 or 1,000,000.
Yes — but remember a "work day" is 8 h, not 24 h. Manually divide hours by 8 for work-day equivalents. We use clock days (24 h) here.