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Converters & Dates

Time Converter

Convert between milliseconds, seconds, minutes, hours, days, weeks, months, and years.

90 minutes equals

Milliseconds5,400,000
Seconds5,400
Hours1.5
Days0.0625
Weeks0.008929
Months (avg)0.002053
Years0.000171

Months and years use their average calendar lengths (30.44 days and 365.2425 days), which is the standard for time conversions.

Convert any span of time

Enter an amount of time in any unit — from milliseconds to years — and instantly see it expressed in every other unit. Useful for programmers working with timestamps, students converting units, project planning, fitness pacing, and billing by the hour.

Worked examples

90 minutes is 1.5 hours or 5,400 seconds. A 30-day sprint is about 0.986 months or 4.29 weeks. 10,000 hours — the famous mastery figure — is about 416.7 days, or 1.14 years of round-the-clock effort (which is why it takes a decade at a few hours a day).

A note on precision

Seconds, minutes, hours, days, and weeks convert exactly. Months and years use calendar averages, because real months differ in length — for date-to-date accuracy, pair this with the Date Difference calculator.

Frequently asked questions

+How many seconds are in a day, a week, a year?

A day has 86,400 seconds (24 × 60 × 60), a week 604,800, and an average year about 31,556,952 — the figure used here accounts for leap years (365.2425 days).

+Why is a month counted as 30.44 days?

Months vary from 28 to 31 days, so conversions use the average: 365.2425 days ÷ 12 ≈ 30.44. For a specific real month, use our Date Difference calculator with actual dates instead.

+How do I convert 90 minutes to hours?

Divide by 60: 90 ÷ 60 = 1.5 hours. Going the other way, multiply hours by 60 — 2.25 hours is 135 minutes.

+What's the difference between this and the date difference calculator?

This tool converts an amount of time between units (e.g. 500 hours → days). The date difference calculator measures the span between two specific calendar dates, respecting real month lengths and leap years.

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