Day to Second

Convert day to second instantly. Type in either field — results update live.

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Time Day Second

1 day = 86,400 seconds

From

Format

Selected d values converted to s using the exact factor from this tool.

Exact conversion factors in both directions, plus a worked example.

1 d = 86400 s

1 s = 0.0000115741 d

To convert day to second, multiply by 86400.

To convert second to day, multiply by 0.0000115741.

Example: convert 10 d to s

10 × 86400 = 864000 s

Short background on the units used in this conversion.

A civil day is exactly 86,400 seconds — 24 hours from midnight to midnight.

Days track weather forecasts, medication schedules, and project deadlines.

The second is the SI base unit of time — defined by cesium atomic clock transitions since 1967.

Seconds time sports events, scientific experiments, and every digital clock and stopwatch.

How many seconds are in one day?

One day equals 86,400 seconds. Multiply your days value by 86,400 to convert to seconds.

What is the conversion formula?

s = d × 86,400

The reverse is d = s × 0.0000115741, using the same exact factors as this converter.

Is this Day to Second converter private?

Yes. All calculations run locally in your browser. Nothing you type is sent to a server.

Jump to any time conversion starting from day — including the reverse direction and every other unit in our dataset.