Online Time Unit Converter

Convert Time.
Instantly & Precisely.

From milliseconds to millennia — convert any time value between 11 units with zero effort. No formulas, no errors, just results.

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How it works

Three Steps, Zero Math

Our converter handles all the arithmetic for you. Here's all you need to do:

STEP 01 📐

Select your source unit

Choose the time unit you're starting from — anything from milliseconds to millennia.

STEP 02 ✏️

Enter your value

Type any number — integers, decimals, large or tiny values are all handled correctly.

STEP 03 ⚡

Read the result instantly

Pick your target unit and the conversion appears immediately. Hit Copy to use it anywhere.

PRO TIP 🔄

Swap with one click

Use the ↕ button to instantly reverse the conversion direction without re-entering values.

PRO TIP 📋

Copy the result instantly

Hit the Copy button next to the result to copy the value to your clipboard — ready to paste anywhere.

⚙️
Who uses it

Built for Anyone Who Works with Time

Time unit conversions appear in surprisingly many professional and everyday contexts. Here's who benefits most:

💻

Developers & Engineers

Convert milliseconds to seconds for API timeouts, cache TTLs, and timestamp logic.

📊

Project Managers

Translate sprint hours into days or weeks for stakeholder reports and timelines.

🎓

Students & Teachers

Check physics and math homework involving time unit conversions without manual calculation.

🔬

Scientists & Researchers

Work with geological timescales, astronomical periods, or lab experiment durations.

✈️

Travel & HR Planners

Calculate leave days, flight durations, and contract periods across different units.

🎬

Media & Production

Convert frame counts, clip durations, and broadcast segments between time formats.

Popular conversions

Most Searched Time Conversions

Jump straight to the conversion you need. Each link opens a dedicated page with detailed examples and a pre-set calculator.

⏱️
Minutes → Hoursmin → hr
→
🕐
Hours → Minuteshr → min
→
📅
Hours → Dayshr → d
→
🌅
Days → Hoursd → hr
→
🗓️
Weeks → Dayswk → d
→
🌙
Months → Daysmo → d
→
📆
Years → Daysyr → d
→
⏲️
Years → Secondsyr → s
→
⌛
Seconds → Minutess → min
→
⚡
Milliseconds → Secondsms → s
→
🏛️
Decades → Yearsdec → yr
→
🗿
Centuries → Yearscent → yr
→
🕰️
Full conversion matrix

All Time Unit Conversions — At a Glance

Every cell links to a dedicated conversion page. Row = From, Column = To.

↔ 110 unique conversion pairs

Did you know?

Time in Numbers — Surprising Facts

31,556,952

Seconds in a year

A tropical year is not exactly 365 days — it's 365.24219 days, which is why we have leap years.

604,800

Seconds in a week

Seven days × 24 hours × 3,600 seconds/hour. It sounds like a lot until you're on a deadline.

86,400

Seconds in a day

The Babylonians divided the day into 24 hours — a convention that has survived 4,000 years unchanged.

1 ms

One millisecond

The blink of an eye takes roughly 150–400 ms. In web performance, 100 ms is the threshold for "instant" response.

10 centuries

= 1 millennium

The year 2000 was widely celebrated as a millennium shift, though technically 2001 began the third millennium.

2,629,746 s

In one average month

A month averages 30.4369 days (1/12 of a year) — not 30 or 31, which affects precise time calculations.

FAQ

Frequently Asked Questions

Divide the number of minutes by 60. For example, 90 minutes ÷ 60 = 1.5 hours. Our converter does this automatically — just select "Minutes" as the source unit and "Hours" as the target, enter your value, and the result appears instantly. You can also use our dedicated minutes to hours page.
There are 31,556,952 seconds in a mean tropical year (365.24219 days × 86,400 seconds/day). Some sources round to 31,536,000 seconds (exactly 365 days), which is slightly less precise. Our converter uses the astronomically accurate value.
For conversion purposes, we use the average month of 30.4369 days (1/12 of a tropical year = 2,629,746 seconds). Calendar months vary between 28 and 31 days, so this average gives the most accurate result for general calculations.
A decade = 10 years, a century = 100 years, and a millennium = 1,000 years. So 1 millennium = 10 centuries = 100 decades. Our converter handles all three, and you can chain conversions in any direction.
Results are computed with up to 12 significant digits using JavaScript's 64-bit floating point arithmetic. Very large or very small values are displayed in scientific notation to preserve readability. For most practical uses this is well within the required precision.
Yes — simply click the ↕ Swap button to reverse the conversion direction. The calculated result becomes the new input and the units are swapped automatically, so you can move back and forth without re-typing values.
Because the Earth takes approximately 365.24219 days to orbit the Sun — that extra 0.24219 days per year is why we add a leap day every 4 years (with century adjustments). Using exactly 365 days would introduce an error of about 6 hours per year, accumulating to 25 days over a century.

Need a specific conversion?

Browse our full library of dedicated conversion pages — each one pre-set, with examples and context.

View all conversions