Time Converter

About time units

This converter uses fixed durations: 1 month = 30 days and 1 year = 365 days. These are practical approximations; calendar months vary between 28 and 31 days, and a leap year has 366 days.

How do I convert between time units?

To convert between time units, multiply the value by its unit's length in milliseconds, then divide by the target unit's length in milliseconds. Example: 1 day equals 1 x 86,400,000 / 3,600,000 = 24 hours; this tool treats 1 month as 30 days and 1 year as 365 days.

Steps to convert between time units

1. Look up the source unit's length in milliseconds (for example, 1 hour = 3,600,000 ms).
2. Multiply the input value by that number to convert it into milliseconds.
3. Look up the target unit's length in milliseconds (for example, 1 day = 86,400,000 ms).
4. Divide the millisecond total by the target unit's length to get the result.
5. For month and year, remember this tool uses fixed lengths (30 days and 365 days) rather than actual calendar months or leap years.

Time conversion formula

• 1 minute = 60,000 ms · 1 hour = 3,600,000 ms · 1 day = 86,400,000 ms
• 1 week = 604,800,000 ms · 1 month (fixed) = 30 days · 1 year (fixed) = 365 days

Common time unit conversions

How many hours is 90 minutes?

90 minutes is 1.5 hours (90 ÷ 60 = 1.5).

How many hours is 3600 seconds?

3,600 seconds is exactly 1 hour (3,600 ÷ 3,600 = 1).

How many seconds is 1 day?

1 day is 86,400 seconds (24 × 3,600).

How many hours is 2 weeks?

2 weeks is 336 hours (2 × 7 × 24).

How many hours is 1 year?

Using this tool's fixed 365-day year, 1 year is 8,760 hours (365 × 24).

How many days is 1 year?

This tool treats 1 year as a fixed 365 days; it does not add an extra day for leap years.

How many days is 1 week?

1 week is 7 days.

How many hours is 1 month?

Using this tool's fixed 30-day month, 1 month is 720 hours (30 × 24).

Example time conversions

Frequently asked questions

Why does this tool use exactly 30 days for a month?

Calendar months vary from 28 to 31 days, so there is no single exact conversion factor. This tool uses a fixed 30-day approximation for quick estimates; for exact calendar math between two specific dates, use a date calculator instead.

Does this tool account for leap years?

No. The year unit here is fixed at 365 days for simplicity. A leap year has 366 days, so conversions involving multi-year spans will be slightly off if leap years fall within the range.

How many seconds are in a day?

There are exactly 86,400 seconds in a day: 24 hours times 60 minutes times 60 seconds. This is the value used as the base for all day-related conversions in this tool.

What is the difference between this tool and a date calculator?

This tool converts fixed durations, like how many hours are in 3 days. A date calculator instead computes the actual calendar difference between two specific dates, correctly handling different month lengths and leap years.

This tool uses fixed unit lengths (30-day months, 365-day years) for quick estimation; for exact durations between real calendar dates, including leap years and variable month lengths, use a date or D-day calculator instead.

Sources: NIST - Units accepted for use with the SI, including minute, hour, and day

Privacy and safety

• Runs in your browser — Everything you type is calculated on your own device. Your inputs are never sent to a utilduck server.
• Encrypted connection — Pages are served over HTTPS, so nobody on the network can read what you load.
• Not shared with third parties — Your inputs are not passed to analytics or advertising services.
• Nothing is stored — Results are not saved to any server, and there is no account to create.

Last updated: 2026-08-17