Time Converter

This time hub converts a duration from one supported unit into a selected destination and a complete reference table. The calculator accepts seconds, minutes, hours, days, weeks, average Gregorian months, and average Gregorian years. Choose both directions; the requested destination is the primary result and the other units remain available for checking.

That makes the page a broad duration reference rather than a calendar calculator. It is best for proportional time amounts: project estimates, study plans, billing blocks, workouts, maintenance intervals, media runtimes, and quick comparisons such as “how many minutes are in 2.5 hours?” It is not the right tool for age, date-to-date spans, time zones, daylight saving changes, or payroll rules that depend on clock-in and clock-out times.

Unit family and definitions

The second is the SI base unit of time and the base used by this calculator. A minute is 60 seconds, an hour is 3,600 seconds, a day is 86,400 seconds, and a week is 604,800 seconds. Those relationships are fixed in the calculator. Months and years are treated as averages: a month is stored as 2,629,800 seconds, and a year is stored as 31,557,600 seconds.

Those average month and year factors are useful for estimates, but they are not calendar-aware. A real month can have 28, 29, 30, or 31 days, and a real year can have 365 or 366 days. If the question is “What date is 90 days from now?” or “How old am I today?”, use a date-aware calculator instead.

Coverage table

The calculator accepts nonnegative values plus source and destination units. It calculates all seven outputs from the same seconds base and labels the selected pair as the primary result.

Formula used by the calculator

First convert the entered duration to seconds:

$\text{seconds} = \text{value} \times \text{seconds per source unit}$

Then divide by the factor for each output unit:

$\text{output units} = \frac{\text{seconds}}{\text{seconds per output unit}}$

The seconds reference row is displayed with no decimals. Other reference values retain up to four decimals, or six for average years. Raw verification keeps the full arithmetic before display rounding.

Worked example matching the calculation

Choose Time value = 2.5, From unit = hours, and To unit = minutes. The hour factor is 3,600 seconds, so the base duration is:

$2.5 \times 3{,}600 = 9{,}000\ \text{seconds}$

The primary result is minutes:

$\frac{9{,}000}{60} = 150\ \text{minutes}$

The supporting rows include 9,000 seconds, 2.5 hours, 0.1042 days, 0.0149 weeks, about 0.0034 average months, and about 0.000285 average years.

For focused day conversions: 3 days = 72 hours, 90 days ≈ 12.857142857 weeks, 90 days ≈ 2.95687885 average Gregorian months, and 1,000 days ≈ 2.737850787 average Gregorian years. The month factor is exactly 365.25 ÷ 12 = 30.4375 days for this tool; it does not represent a particular calendar month.

Picking the right sub-converter

Use this hub when you want the full duration table at once. For a single direction, the hours to minutes converter is easier to share in a classroom or worksheet. The hours to seconds converter keeps the focus on small time units. The days to weeks calculator is a better match for schedules expressed in calendar-like day blocks, while the day converter and hour converter provide narrower unit families. Use the time duration calculator when you need elapsed time between two clock values, and the time card calculator when work shifts, breaks, and payroll hours are involved.

For life spans, birthdays, and exact age, use the age calculator. For planning across real dates, choose a date-specific calculator because month length and leap years are not captured by this simple average-month conversion.

Domains and pitfalls

Project planning often uses hours and days because they are easy to assign to tasks, but a “day” in this calculator is always 24 hours. Business days, school days, and work shifts are policy definitions, not unit definitions. Fitness plans may convert minutes to hours or weeks; billing may convert minutes to decimal hours; software logs may convert seconds to minutes for readability.

The most important pitfall is treating average months as calendar months. Three average months in this calculator equals 7,889,400 seconds, not necessarily the number of seconds between January 15 and April 15. Another common issue is decimal notation: 1.5 hours is 1 hour 30 minutes, but 1.30 hours is 1 hour 18 minutes because the decimal part is a fraction of an hour.

Sources

• BIPM, Measurement units — international measurement system context for the second.
• NIST, SI Units — SI unit reference for time notation and base units.
• NIST, Special Publication 811 — guidance on SI style and unit-symbol presentation.