Convert Hours (h) to Seconds (s)

Q: How many seconds in an hour?

Exactly 3,600 seconds (60 × 60).

Q: How many seconds in 8 hours?

28,800 seconds — a standard 8-hour work day.

1 hour equals 3600 seconds.

Formula: s = h × 3600

Hour to Second Converter

What Is an Hour?

The hour (h) equals exactly 60 minutes or 3,600 seconds. It is accepted for use with the SI system.

What Is a Second?

The second (s) is the SI base unit of time, defined as 9,192,631,770 periods of cesium-133 radiation (since 1967).

Hours to Seconds Formula

seconds = hours × 3,600 exact

This is exact: 1 hour = 60 minutes × 60 seconds = 3,600 seconds.

Worked Example

Convert 8 hours (a work day) to seconds:

8 × 3,600 = 28,800 seconds

Common Hours to Seconds Conversions

Hours	Seconds	Context
0.5 h	1,800 s	Half hour
1 h	3,600 s	Standard hour
2 h	7,200 s	Movie length / exam
4 h	14,400 s	Half work day
8 h	28,800 s	Standard work day
12 h	43,200 s	Half day / nursing shift
24 h	86,400 s	Full day

When You Need This Conversion

Programming: Timers, countdowns, and interval functions use seconds or milliseconds.
Science: Experimental durations are logged in seconds for precision.
Sports: Race times and records use seconds for comparison.

Frequently Asked Questions

How many seconds in an hour?

Exactly 3,600 seconds (60 × 60).

How many seconds in 2 hours?

7,200 seconds (2 × 3,600).

How many seconds in 8 hours?

28,800 seconds — a standard 8-hour work day.

How many seconds in half an hour?

1,800 seconds (3,600 ÷ 2).

Common Hour to Second Conversions

Hour to Second (Part 1)

Hour	Second	Actions
1 hour	3600 seconds
2 hours	7200 seconds

Hour to Second (Part 2)

Hour	Second	Actions
8 hours	28800 seconds
24 hours	86400 seconds

Hours to seconds Conversion Table

Reference table with common hours to seconds conversions. All values calculated with high precision.

Hours to Seconds Table
0.0001 to 12

Hours	Seconds	Actions
0.0001 h	0.36 s
0.00025 h	0.9 s
0.0005 h	1.8 s
0.001 h	3.6 s
0.0025 h	9 s
0.005 h	18 s
0.01 h	36 s
0.025 h	90 s
0.05 h	180 s
0.1 h	360 s
14 h	900 s
12 h	1800 s

Hours to Seconds Table
1 to 100000

Hours	Seconds	Actions
1 h	3600 s
2 12 h	9000 s
5 h	18000 s
10 h	36000 s
25 h	90000 s
50 h	180000 s
100 h	360000 s
250 h	900000 s
500 h	1800000 s
1000 h	3600000 s
2500 h	9000000 s
5000 h	1.8 × 10⁷ s
10000 h	3.6 × 10⁷ s
25000 h	9 × 10⁷ s
50000 h	1.8 × 10⁸ s
100000 h	3.6 × 10⁸ s

Seconds to Hours Table
1 to 5000

Seconds	Hours	Actions
1 s	0.000277778 h
2 12 s	0.000694444 h
5 s	0.00138889 h
10 s	0.00277778 h
25 s	0.00694444 h
50 s	0.0138889 h
100 s	0.0277778 h
250 s	0.0694444 h
500 s	0.138889 h
1000 s	0.277778 h
2500 s	0.694444 h
5000 s	1.38889 h

Seconds to Hours Table
10000 to 1 × 10⁹

Seconds	Hours	Actions
10000 s	2.77778 h
25000 s	6.94444 h
50000 s	13.8889 h
100000 s	27.7778 h
250000 s	69.4444 h
500000 s	138.889 h
1000000 s	277.778 h
2500000 s	694.444 h
5000000 s	1388.89 h
10000000 s	2777.78 h
2.5 × 10⁷ s	6944.44 h
5 × 10⁷ s	13888.9 h
1 × 10⁸ s	27777.8 h
2.5 × 10⁸ s	69444.4 h
5 × 10⁸ s	138889 h
1 × 10⁹ s	277778 h

Looking for the reverse? Convert Second to Hour

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km/h to mph — Speed = distance per unit time

Hours to Decimal Converter — for payroll and timesheets
Military Time Converter — 24-hour ↔ 12-hour clock
Days From Today — date math from today
Days Until — countdown to any holiday or date
Time References — seconds, minutes, hours, weeks per day/year

Conversion factors verified against NIST, BIPM, ISO 8601 Second defined by Cs-133 transition (SI, BIPM). Last reviewed: March 2026

By Adilson Fernandes

Reviewed by Tiago Fernandes

All unit conversions on CoolConversion use conversion factors defined or documented by internationally recognised standards bodies (such as ISO and NIST), including both SI and non-SI units.