Conversion formula

The conversion factor from seconds to hours is 0.00027777777777778, which means that 1 second is equal to 0.00027777777777778 hours:

1 s = 0.00027777777777778 hr

To convert 21 seconds into hours we have to multiply 21 by the conversion factor in order to get the time amount from seconds to hours. We can also form a simple proportion to calculate the result:

1 s → 0.00027777777777778 hr

21 s → T_(hr)

Solve the above proportion to obtain the time T in hours:

T_(hr) = 21 s × 0.00027777777777778 hr

T_(hr) = 0.0058333333333333 hr

The final result is:

21 s → 0.0058333333333333 hr

We conclude that 21 seconds is equivalent to 0.0058333333333333 hours:

21 seconds = 0.0058333333333333 hours

Alternative conversion

We can also convert by utilizing the inverse value of the conversion factor. In this case 1 hour is equal to 171.42857142857 × 21 seconds.

Another way is saying that 21 seconds is equal to 1 ÷ 171.42857142857 hours.

Approximate result

For practical purposes we can round our final result to an approximate numerical value. We can say that twenty-one seconds is approximately zero point zero zero six hours:

21 s ≅ 0.006 hr

An alternative is also that one hour is approximately one hundred seventy-one point four two nine times twenty-one seconds.

Conversion table

seconds to hours chart

For quick reference purposes, below is the conversion table you can use to convert from seconds to hours