Seconds to Milliseconds (s to ms)

Formula

1 s = 1000 ms

milliseconds = seconds × 1000 — reverse: seconds = milliseconds × 0.001

The factor is derived from the SI definitions of both units (base unit: s) as listed in NIST SP 811; results on this page are shown to 6 significant figures, the API returns up to 12.

Worked examples

• 5 s = 5000 ms
• 12.5 s = 12500 ms
• 100 s = 100000 ms

Seconds to milliseconds conversion table

FAQ

How many milliseconds are in one second?

1 s = 1000 ms. The factor comes from the SI definitions of both units (NIST SP 811 / BIPM), so it is exact or correct to at least 10 significant figures.

What is the formula to convert seconds to milliseconds?

Multiply the value in seconds by 1000: milliseconds = seconds × 1000. For example, 5 s = 5000 ms.

How do I convert milliseconds back to seconds?

Multiply by the inverse factor 0.001 (seconds = milliseconds × 0.001), or use the milliseconds-to-seconds page.

Related conversions

• Milliseconds to seconds (reverse)
• Time Converter — all time units in one tool
• Hours to Minutes
• Minutes to Hours
• Minutes to Seconds
• Seconds to Minutes
• Days to Hours
• Hours to Days
• Weeks to Days
• Days to Weeks

Machine access

• API: GET https://tttkmbb.com/api/v1/convert?value=5&from_unit=s&to_unit=ms
• MCP: server https://tttkmbb.com/mcp, tool convert_units with {"value":5,"from_unit":"s","to_unit":"ms"}
• Markdown: https://tttkmbb.com/conversion/seconds-to-milliseconds.md · JSON: https://tttkmbb.com/conversion/seconds-to-milliseconds.json (add ?value= for a result) · Units: /api/v1/units?quantity=time
• OpenAPI operationId: convert_units. Freshness: static. Authentication: none.

Sources

• NIST Special Publication 811 – Guide for the Use of the International System of Units (SI), Appendix B conversion factors (standard)
• BIPM – The International System of Units (SI Brochure, 9th edition) (standard)
• Wikipedia – Conversion of units (reference)