Time Converter
Convert time between seconds, minutes, hours, days, weeks, months, and years. Used for scheduling, project planning, scientific calculations, and payroll. See also our Hours Calculator and Days Calculator.
Value:
Popular Time Converters:
What is a Time Converter?
A time converter is a tool that converts between different units of time such as seconds, minutes, hours, days, weeks, months, and years. It is useful for scheduling, project planning, scientific calculations, and any situation where you need to express time durations in different units.
History of Time Measurement
The Egyptians divided the day into 24 hours around 1500 BCE, and the Babylonians introduced the base-60 system giving us 60 minutes per hour and 60 seconds per minute. In 1967, the SI second was redefined based on cesium-133 atomic vibrations, providing precision to within one second over millions of years.
About This Time Converter
This time converter supports 23 different units including seconds, minutes, hours, days, weeks, months, years, decades, centuries, millennia, milliseconds, microseconds, nanoseconds, picoseconds, femtoseconds, attoseconds, fortnight, and Planck time.
Understanding Time Measurement and Conversion
Time is the dimension in which events occur in sequence — it governs schedules, deadlines, processes, and the fundamental laws of physics. Unlike most physical quantities, time uses a mixed-radix system in everyday life: 60 seconds in a minute, 60 minutes in an hour, 24 hours in a day, 7 days in a week, and varying days in months and years. This irregularity makes time conversion less intuitive than metric unit conversions.
The SI unit of time is the second, currently defined by the radiation frequency of cesium-133 atoms (9,192,631,770 oscillations = 1 second). For scientific and computing applications, everything reduces to seconds or fractions thereof (milliseconds, microseconds, nanoseconds). But human life organizes around hours, days, weeks, months, and years — units rooted in astronomy (Earth's rotation and orbit) rather than decimal convenience.
Time conversion is needed constantly: project management (converting hours to days), computing (milliseconds to seconds), science (years to seconds for rate calculations), sports timing (minutes and seconds), and international scheduling (time zones effectively require adding or subtracting hours). The non-decimal relationships between time units mean you cannot simply slide a decimal point — you must multiply or divide by 60, 24, 7, or 365.25 depending on the units.
How to Convert Between Time Units (Step-by-Step)
Time conversion requires careful attention to the non-decimal relationships between units. The second is the base SI unit, but in practice you will often convert between hours, minutes, and days.
- Identify your source and target time units (e.g., hours to seconds, or days to minutes).
- Map the chain of conversion factors: seconds ↔ minutes (×60) ↔ hours (×60) ↔ days (×24) ↔ weeks (×7).
- Multiply through the chain: e.g., 3.5 hours → minutes = 3.5 × 60 = 210 minutes → seconds = 210 × 60 = 12,600 seconds.
- For years: 1 year = 365.25 days (average accounting for leap years) = 8,766 hours = 525,960 minutes = 31,557,600 seconds.
- Verify with a sanity check: 1 day = 86,400 seconds (24 × 60 × 60). If your answer for "2 days in seconds" is not close to 172,800, recheck your math.
Essential Time Conversion Formulas
The key relationships between time units. Note the non-decimal factors (60, 24, 7) that make time conversion distinctive:
- 1 minute = 60 seconds
- 1 hour = 60 minutes = 3,600 seconds
- 1 day = 24 hours = 1,440 minutes = 86,400 seconds
- 1 week = 7 days = 168 hours = 604,800 seconds
- 1 year (average) = 365.25 days = 8,766 hours = 31,557,600 seconds
- 1 millisecond = 0.001 seconds
- 1 microsecond = 0.000001 seconds = 10⁻⁶ s
- 1 nanosecond = 10⁻⁹ seconds
Worked Examples — Time Conversions
Example 1: A manufacturing process takes 7,200 seconds. Express this in hours and minutes.
Solution:
Convert to minutes: 7,200 ÷ 60 = 120 minutes.
Convert to hours: 120 ÷ 60 = 2 hours.
So 7,200 seconds = 2 hours exactly.
Answer: 7,200 seconds = 120 minutes = 2 hours.
Example 2: A project has a deadline of 1,000 hours. How many standard work weeks is that (40 hr/week)?
Solution:
Divide by hours per work week: 1,000 ÷ 40 = 25 work weeks.
In calendar time: 25 weeks × 7 days = 175 days ≈ 5.8 months.
Answer: 1,000 hours = 25 standard work weeks (about 5.8 months calendar time).
Example 3: Light travels 1 light-year in 1 year. How many seconds does that take?
Solution:
1 year = 365.25 days (accounting for leap years).
365.25 × 24 = 8,766 hours.
8,766 × 3,600 = 31,557,600 seconds.
Answer: 1 year = 31,557,600 seconds (approximately 3.16 × 10⁷ s).
Example 4: A computer operation takes 250 microseconds. How many operations can it perform per second?
Solution:
250 microseconds = 250 × 10⁻⁶ seconds = 0.00025 seconds per operation.
Operations per second = 1 ÷ 0.00025 = 4,000 operations/second.
Answer: At 250 μs per operation, the computer performs 4,000 operations per second.
Example 5: A runner completes a marathon in 3 hours, 45 minutes, 30 seconds. Express the total time in seconds.
Solution:
Hours to seconds: 3 × 3,600 = 10,800 s.
Minutes to seconds: 45 × 60 = 2,700 s.
Add seconds: 10,800 + 2,700 + 30 = 13,530 s.
Answer: 3h 45m 30s = 13,530 seconds.
Quick Reference — Common Time Conversions
Essential time unit relationships for everyday and scientific use.
| From | To |
|---|---|
| 1 second | 1,000 milliseconds |
| 1 minute | 60 seconds |
| 1 hour | 3,600 seconds |
| 1 day | 86,400 seconds |
| 1 week | 604,800 seconds |
| 1 month (avg) | 30.437 days |
| 1 year (avg) | 365.25 days |
| 1 year | 31,557,600 s |
| 1 decade | 10 years |
| 1 century | 100 years |
| 1 millisecond | 0.001 s |
| 1 microsecond | 10⁻⁶ s |
| 1 nanosecond | 10⁻⁹ s |
| 1 fortnight | 14 days |
Time Measurement Systems and Standards
The modern second is defined atomically: 9,192,631,770 periods of the radiation from cesium-133 atoms. This gives extraordinary precision — atomic clocks lose less than one second in 300 million years. From this base, we build up: 60 seconds = 1 minute, 60 minutes = 1 hour, 24 hours = 1 day. These seemingly arbitrary factors (60, 24) come from ancient Babylon (base-60 counting) and Egypt (12-hour day/night divisions).
Calendar time introduces further complexity. A solar year is approximately 365.2422 days, which is why we need leap years (every 4 years, except centuries, except every 400 years — the Gregorian calendar rule). The Julian year (exactly 365.25 days) is used in astronomy. Months vary from 28 to 31 days with no regular pattern, making month-based calculations imprecise unless you specify which months.
For scientific and computing purposes, time is often measured in pure seconds from a reference point. Unix time counts seconds since January 1, 1970 (UTC). GPS time counts seconds since January 6, 1980. These systems avoid the complexity of calendars entirely, though they must account for leap seconds (occasional one-second adjustments to keep atomic time aligned with Earth's slightly irregular rotation).
Where Time Conversion Matters
Project Management
Converting person-hours to person-days or weeks is fundamental to scheduling. A 2,000-hour project needs 50 work-weeks of effort (at 40 hrs/week), but with a team of 4, it might take 12.5 calendar weeks.
Computing & Networking
Latency is measured in milliseconds (ms), CPU cycles in nanoseconds (ns), and timeouts in seconds. Converting between these scales is essential for performance optimization and debugging.
Science & Physics
Rate calculations require consistent time units. A reaction rate in mol/min must be converted to mol/s for SI calculations. Half-lives of radioactive elements span nanoseconds to billions of years.
Sports & Athletics
Race times use hours:minutes:seconds format but pace calculations need minutes per mile/km. A 3:45 marathon is 225 minutes; dividing by 26.2 miles gives 8:35 per mile pace.
Finance & Interest
Interest calculations depend on time period definitions. Annual rates converted to daily use 360 or 365 days depending on convention. Compound interest frequency (monthly, daily) requires converting annual rates.
Space Science
Spacecraft distances are measured in light-time: light-seconds, light-minutes (Sun to Earth ≈ 8.3 light-minutes), light-years. Converting to standard distance units requires knowing c = 299,792,458 m/s.
Common Mistakes in Time Conversion
The most frequent error is treating months as exactly 30 days or years as exactly 365 days. An average month is 30.437 days, and an average year is 365.25 days (or 365.2422 for the tropical year). Another common mistake is the decimal-time confusion: 1.5 hours is 1 hour 30 minutes, NOT 1 hour 50 minutes. When a calculator shows 2.75 hours, that means 2 hours and 0.75 × 60 = 45 minutes, not 2 hours 75 minutes. Finally, forgetting the AM/PM vs 24-hour conversion: 1:00 PM = 13:00, not 1:00 in 24-hour format.
Decimal Time vs Sexagesimal Time
Our time system is sexagesimal (base-60), inherited from Babylonian mathematics. This makes mental arithmetic harder than decimal would be. Various attempts to decimalize time have been made — the French Revolutionary decimal time (10 hours per day, 100 minutes per hour) lasted only 17 months. Today, "decimal hours" (where 1.5 hours = 90 minutes) are used in payroll and project tracking to simplify calculations. If you see time written as 7.75 hours on a timesheet, that means 7 hours and 45 minutes (0.75 × 60 = 45), not 7 hours and 75 minutes.
Key Takeaways
- Time uses non-decimal factors: 60 (seconds/minutes, minutes/hours), 24 (hours/day), 7 (days/week).
- The SI unit is the second, defined by atomic radiation of cesium-133.
- Key constants: 1 hour = 3,600 s, 1 day = 86,400 s, 1 year ≈ 31.56 million seconds.
- For year calculations, use 365.25 days/year to account for leap years (Julian year).
- Sub-second scales: milli (10⁻³), micro (10⁻⁶), nano (10⁻⁹), pico (10⁻¹²).
- Calendar months are irregular (28-31 days), making "months" an imprecise time unit for calculations.
Metric Conversion Factor Tables for Time Converter
| Units to convert | Multiply By The Number | Convert as Unit |
|---|---|---|
| Second (s) | 0.016666667 | Minute (min) |
| Second (s) | 0.000277778 | Hour (h) |
| Second (s) | 1000 | Millisecond (ms) |
| Minute (min) | 60 | Second (s) |
| Minute (min) | 0.016666667 | Hour (h) |
| Hour (h) | 60 | Minute (min) |
| Hour (h) | 3600 | Second (s) |
| Hour (h) | 0.041666667 | Day (d) |
| Day (d) | 24 | Hour (h) |
| Day (d) | 1440 | Minute (min) |
| Day (d) | 86400 | Second (s) |
| Week | 7 | Day (d) |
| Week | 168 | Hour (h) |
| Month (mo) | 30.4375 | Day (d) |
| Year (y) | 365 | Day (d) |
| Year (y) | 12 | Month (mo) |
| Year (y) | 52.1429 | Week |
| Year (y) | 8760 | Hour (h) |
| Decade | 10 | Year (y) |
| Century | 100 | Year (y) |
| Millennium | 1000 | Year (y) |
Timeconverters & it's abbreviations
| Unit | Abbreviation | Unit | Abbreviation | Unit | Abbreviation |
|---|---|---|---|---|---|
| second | s | minute | min | hour | h |
| day | d | week | wk | month | mo |
| year | y yr | decade | dec | century | c |
| millennium | - | millisecond | ms | microsecond | µs |
| nanosecond | ns | picosecond | ps | femtosecond | fs |
| attosecond | as | fortnight | - | Planck time | tP |
Frequently Asked Questions
How many seconds are in a day?
There are exactly 86,400 seconds in one day (24 hours × 60 minutes × 60 seconds).
How many hours are in a year?
A standard year has 8,760 hours (365 days × 24 hours). A leap year has 8,784 hours (366 days × 24 hours).
How many weeks are in a year?
There are approximately 52.143 weeks in a year (365 days ÷ 7 days per week). This means a year has 52 full weeks plus 1 extra day (or 2 in a leap year).
How many days are in a month?
Months vary from 28 to 31 days. The average month length is approximately 30.4375 days (365.25 days ÷ 12 months).
What is a nanosecond?
A nanosecond is one billionth of a second (10⁻⁹ seconds). Light travels approximately 30 centimeters (about 1 foot) in one nanosecond.
Complete list of Time conversion units and its conversion.
- 1 second [s] = 1000 millisecond [ms]
seconds to milliseconds → - 1 second [s] = 0.016666667 minute [min]
seconds to minutes → - 1 second [s] = 0.000277778 hour [h]
seconds to hours →
- 1 minute [min] = 60 second [s]
minutes to seconds → - 1 minute [min] = 0.016666667 hour [h]
minutes to hours → - 1 minute [min] = 0.0006944444 day [d]
minutes to days →
- 1 hour [h] = 0.041666667 day [d]
hours to days → - 1 hour [h] = 0.005952381 week
hours to weeks → - 1 day [d] = 24 hour [h]
days to hours →
- 1 day [d] = 0.0027397260 year [y]
days to years → - 1 week = 7 day [d]
weeks to days → - 1 week = 168 hour [h]
weeks to hours →
- 1 month [mo] = 4.3482143 week
months to weeks → - 1 year [y] = 365 day [d]
years to days → - 1 year [y] = 12 month [mo]
years to months →
- 1 year [y] = 31536000 second [s]
years to seconds → - 1 millisecond [ms] = 0.001 second [s]
milliseconds to seconds → - 1 millisecond [ms] = 1000 microsecond [µs]
milliseconds to microseconds →
- 1 nanosecond [ns] = 1000 picosecond [ps]
nanoseconds to picoseconds → - 1 decade = 10 year [y]
decades to years → - 1 century = 100 year [y]
centuries to years →
- 1 second [s] = 0.0000115741 day [d]
seconds to days → - 1 second [s] = 1000000 microsecond [µs]
seconds to microseconds → - 1 second [s] = 1000000000 nanosecond [ns]
seconds to nanoseconds →
- 1 minute [min] = 60000 millisecond [ms]
minutes to milliseconds → - 1 hour [h] = 60 minute [min]
hours to minutes → - 1 hour [h] = 3600 second [s]
hours to seconds →
- 1 day [d] = 1440 minute [min]
days to minutes → - 1 day [d] = 86400 second [s]
days to seconds → - 1 day [d] = 0.0328767123 month [mo]
days to months →
- 1 week = 10080 minute [min]
weeks to minutes → - 1 month [mo] = 30.4375 day [d]
months to days → - 1 month [mo] = 730.5 hour [h]
months to hours →
- 1 year [y] = 52.1428571 week
years to weeks → - 1 year [y] = 8760 hour [h]
years to hours → - 1 year [y] = 525600 minute [min]
years to minutes →
- 1 microsecond [µs] = 0.001 millisecond [ms]
microseconds to milliseconds → - 1 microsecond [µs] = 1000 nanosecond [ns]
microseconds to nanoseconds → - 1 nanosecond [ns] = 0.001 microsecond [µs]
nanoseconds to microseconds →
- 1 millennium = 1000 year [y]
millennia to years → - 1 fortnight = 14 day [d]
fortnights to days → - 1 fortnight = 2 week
fortnights to weeks →