Time Converter | Convert Between All Time Units

How to Convert Units of Time

Converting time units is straightforward because all measurements are relative to a single base unit: the second. The general method involves a two-step process (though our calculator does this instantly):

Convert to Base: Multiply your starting value by its conversion factor to get seconds.
Convert to Target: Divide that result by the target unit's conversion factor.

For example, to convert 2.5 hours into seconds, you simply multiply:
2.5 hours × 3,600 = 9,000 seconds.

Time Unit Conversion Table

Unit	Symbol	Value in Seconds (s)	Value in Days (d)
Nanosecond	ns	0.000000001	~1.157e-14
Microsecond	µs	0.000001	~1.157e-11
Millisecond	ms	0.001	~1.157e-8
Second	s	1	~0.00001157
Minute	min	60	0.000694
Hour	h	3,600	0.041667
Day	d	86,400	1
Week	wk	604,800	7
Month (Avg)	mo	2,629,746	30.436875
Year (Gregorian)	yr	31,556,952	365.2425

Common Time Conversions

Seconds in a Minute: 60 seconds

Seconds in an Hour: 3,600 seconds

Seconds in a Day: 86,400 seconds

Minutes in a Day: 1,440 minutes

Hours in a Week: 168 hours

Days in a Month: 30.44 days (average)

Weeks in a Year: 52.1775 weeks

Seconds in a Year: 31,556,952 seconds

Time Conversion Examples

Example 1: Convert 3.5 hours to minutes

Formula: Hours × 60 = Minutes

Calculation: 3.5 × 60 = 210 minutes

Example 2: Convert 7,200 seconds to hours

Formula: Seconds ÷ 3,600 = Hours

Calculation: 7,200 ÷ 3,600 = 2 hours

Example 3: Convert 500 milliseconds to seconds

Formula: Milliseconds ÷ 1,000 = Seconds

Calculation: 500 ÷ 1,000 = 0.5 seconds

Understanding Time Units

Time measurement has evolved from tracking celestial bodies to atomic precision.

Second (s): The SI base unit of time. Originally defined by Earth's rotation, it is now defined by the radiation frequency of the cesium-133 atom.
Day (d): Based on one full rotation of the Earth. While not perfectly constant, we standardize it as 24 hours.
Month (mo): Historically based on the lunar cycle (~29.5 days). In the Gregorian calendar, months vary from 28 to 31 days.
Year (yr): The time it takes Earth to orbit the Sun. A tropical year is approximately 365.24219 days.

Assumptions & Methodology

To ensure high precision, this calculator uses the following standards:

1 Year = 365.2425 days: This is the Gregorian calendar average, accounting for leap years (including the 400-year exception rule).
1 Month = 30.436875 days: Calculated as (365.2425 days / 12).
1 Day = 86,400 seconds: Standard SI definition (leap seconds are ignored for general conversion).

Frequently Asked Questions

How many seconds are in a day?

There are 86,400 seconds in a day. This is calculated as 24 hours × 60 minutes × 60 seconds = 86,400.

How many seconds are in a year?

Using the Gregorian calendar average of 365.2425 days per year, there are approximately 31,556,952 seconds in a year.

How do you convert hours to minutes?

Multiply the number of hours by 60. For example, 2.5 hours × 60 = 150 minutes.

Why do month conversions differ between calculators?

Different calculators use different assumptions. Some use 30 days, others use 30.4167 days (365/12). We use the precise Gregorian average of 30.4369 days (365.2425/12) to account for leap years accurately.

How accurate is this time converter?

Our converter uses the Gregorian calendar average for year and month conversions, which is the most widely accepted standard for general use. All other conversions (seconds, minutes, hours, days, weeks) are mathematically exact.

Can I convert negative time values?

Yes. Negative values are supported and converted normally. This is useful for calculating time differences or durations "ago".