Time Converter Online — Seconds, Minutes, Hours & Days Free

Time Unit Conversion Factors

How to Use the Time Converter

1. Enter the duration. Type the number you want to convert.
2. Select the source unit. Choose seconds, minutes, hours, days, weeks, months, or years.
3. Read the results. All equivalent durations in other units appear instantly.

Common Time Conversion Use Cases

Programming and performance monitoring

Log files, database query times, and API response times are often recorded in milliseconds or microseconds. Converting these to seconds or minutes helps assess whether a process is within acceptable latency bounds. A timeout of 30,000 ms is 30 seconds; a query taking 1,200 ms is 1.2 seconds — whether that is acceptable depends on context.

Project and billing calculations

Freelancers and agencies often bill in hours but track time in minutes. Converting 187 minutes to hours (3 hours 7 minutes, or 3.117 hours) ensures accurate invoice calculations. The meeting cost calculator uses hourly rates to calculate meeting costs — convert your tracked time to hours first.

Age and duration milestones

How many seconds old are you? How many days until an event? How many weeks in a pregnancy? Time converters answer these directly. A full-term pregnancy is 280 days (40 weeks); the pregnancy due date calculator gives the actual date from a last menstrual period or conception date.

Year and Month Approximations

Months and years have variable lengths, so time converters use average values for these conversions:

• Average month: 365.25 ÷ 12 = 30.4375 days (accounts for leap years over a 4-year cycle)
• Average year: 365.25 days (Gregorian calendar average including leap years)
• Leap year: 366 days; occurs in years divisible by 4, except century years unless also divisible by 400

For exact calendar date arithmetic — "how many days between 15 March and 30 September?" — use the age calculator with custom start and end dates rather than multiplying average month values.

Common Questions

How many seconds are in a year?

A standard 365-day year has 365 × 24 × 60 × 60 = 31,536,000 seconds. A leap year has 31,622,400 seconds. The average Gregorian year (365.25 days) has 31,557,600 seconds. The "one billion seconds" milestone falls at approximately 31.7 years of age.

What is the difference between a Julian year and a Gregorian year?

A Julian year is exactly 365.25 days, used in astronomy as a convenient unit. The Gregorian year averages 365.2425 days (adjusting for century years not being leap years unless divisible by 400). For most practical purposes the difference is negligible — it amounts to about 11 minutes per year.

How do I convert decimal hours to hours and minutes?

Multiply the decimal part by 60. For example, 3.75 hours = 3 hours + (0.75 × 60) = 3 hours 45 minutes. To convert minutes back to decimal hours, divide by 60: 45 minutes = 45 ÷ 60 = 0.75 hours.