# Kilometers per hour to Meters per second (km/h to m/s)

> Convert kilometers per hour to meters per second: 1 km/h = 0.277778 m/s. Exact conversion factor, formula, 22-row table and worked examples, with JSON API and MCP access.

- Page id: `kmh-to-meters-per-second` · Quantity: Speed (`speed`, base unit m/s) · Tool: `convert_units`
- Canonical page: https://tttkmbb.com/conversion/kmh-to-meters-per-second · This document: https://tttkmbb.com/conversion/kmh-to-meters-per-second.md · JSON: https://tttkmbb.com/conversion/kmh-to-meters-per-second.json (add `?value=` for a result)

## Formula

- `1 km/h = 0.277778 m/s`
- `meters per second = kilometers per hour × 0.2777777778`
- Reverse: `kilometers per hour = meters per second × 3.6`

The factor follows from the SI definitions of both units (NIST SP 811); values below are rounded to 6 significant figures, the API returns up to 12.

## Worked examples

- 5 km/h = 1.38889 m/s
- 12.5 km/h = 3.47222 m/s
- 100 km/h = 27.7778 m/s

## Conversion table

| Kilometers per hour (km/h) | Meters per second (m/s) |
| --- | --- |
| 1 | 0.277778 |
| 2 | 0.555556 |
| 3 | 0.833333 |
| 4 | 1.11111 |
| 5 | 1.38889 |
| 6 | 1.66667 |
| 7 | 1.94444 |
| 8 | 2.22222 |
| 9 | 2.5 |
| 10 | 2.77778 |
| 15 | 4.16667 |
| 20 | 5.55556 |
| 25 | 6.94444 |
| 30 | 8.33333 |
| 40 | 11.1111 |
| 50 | 13.8889 |
| 75 | 20.8333 |
| 100 | 27.7778 |
| 200 | 55.5556 |
| 250 | 69.4444 |
| 500 | 138.889 |
| 1000 | 277.778 |

## API

- `GET https://tttkmbb.com/api/v1/convert?value=5&from_unit=km%2Fh&to_unit=m%2Fs` → unified JSON envelope with `result.values.result`, `formula`, `factor`, `sources`, `freshness`
- MCP: server `https://tttkmbb.com/mcp`, tool `convert_units` with `{"value":5,"from_unit":"km/h","to_unit":"m/s"}`
- All speed units: https://tttkmbb.com/api/v1/units?quantity=speed · full converter: [Speed Converter](https://tttkmbb.com/conversion/speed.md)
- Authentication: none. Freshness: `static` (fixed conversion factors).

## FAQ

**How many meters per second are in one kilometer per hour?**

1 km/h = 0.277778 m/s. 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 kilometers per hour to meters per second?**

Multiply the value in kilometers per hour by 0.2777777778: meters per second = kilometers per hour × 0.2777777778. For example, 5 km/h = 1.38889 m/s.

**How do I convert meters per second back to kilometers per hour?**

Multiply by the inverse factor 3.6 (kilometers per hour = meters per second × 3.6), or use the meters per second-to-kilometers per hour page.

## Related conversions

- [Meters per second to kilometers per hour](https://tttkmbb.com/conversion/meters-per-second-to-kmh.md) (reverse)
- [Kilometers per hour to Miles per hour](https://tttkmbb.com/conversion/kmh-to-mph.md)
- [Miles per hour to Kilometers per hour](https://tttkmbb.com/conversion/mph-to-kmh.md)
- [Meters per second to Miles per hour](https://tttkmbb.com/conversion/meters-per-second-to-mph.md)
- [Miles per hour to Meters per second](https://tttkmbb.com/conversion/mph-to-meters-per-second.md)
- [Knots to Kilometers per hour](https://tttkmbb.com/conversion/knots-to-kmh.md)
- [Kilometers per hour to Knots](https://tttkmbb.com/conversion/kmh-to-knots.md)
- [Knots to Miles per hour](https://tttkmbb.com/conversion/knots-to-mph.md)
- [Miles per hour to Knots](https://tttkmbb.com/conversion/mph-to-knots.md)

## Data Sources

- NIST Special Publication 811 – Guide for the Use of the International System of Units (SI), Appendix B conversion factors — https://www.nist.gov/pml/special-publication-811 (standard, retrieved 2026-09-24)
- BIPM – The International System of Units (SI Brochure, 9th edition) — https://www.bipm.org/en/publications/si-brochure (standard, retrieved 2026-09-24)
- Wikipedia – Conversion of units — https://en.wikipedia.org/wiki/Conversion_of_units (reference, retrieved 2026-09-24)