# Mach (sea level) to Kilometers per hour (mach to km/h)

> Convert Mach (sea level) to kilometers per hour: 1 mach = 1225.06 km/h. Exact conversion factor, formula, 22-row table and worked examples, with JSON API and MCP access.

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

## Formula

- `1 mach = 1225.06 km/h`
- `kilometers per hour = Mach (sea level) × 1225.0584`
- Reverse: `Mach (sea level) = kilometers per hour × 0.0008162876153`

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 mach = 6125.29 km/h
- 12.5 mach = 15313.2 km/h
- 100 mach = 122506 km/h

## Conversion table

| Mach (sea level) (mach) | Kilometers per hour (km/h) |
| --- | --- |
| 1 | 1225.06 |
| 2 | 2450.12 |
| 3 | 3675.18 |
| 4 | 4900.23 |
| 5 | 6125.29 |
| 6 | 7350.35 |
| 7 | 8575.41 |
| 8 | 9800.47 |
| 9 | 11025.5 |
| 10 | 12250.6 |
| 15 | 18375.9 |
| 20 | 24501.2 |
| 25 | 30626.5 |
| 30 | 36751.8 |
| 40 | 49002.3 |
| 50 | 61252.9 |
| 75 | 91879.4 |
| 100 | 122506 |
| 200 | 245012 |
| 250 | 306265 |
| 500 | 612529 |
| 1000 | 1225060 |

## API

- `GET https://tttkmbb.com/api/v1/convert?value=5&from_unit=mach&to_unit=km%2Fh` → 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":"mach","to_unit":"km/h"}`
- 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 kilometers per hour are in one Mach?**

1 mach = 1225.06 km/h. 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 Mach (sea level) to kilometers per hour?**

Multiply the value in Mach (sea level) by 1225.0584: kilometers per hour = Mach (sea level) × 1225.0584. For example, 5 mach = 6125.29 km/h.

**How do I convert kilometers per hour back to Mach (sea level)?**

Multiply by the inverse factor 0.0008162876153 (Mach (sea level) = kilometers per hour × 0.0008162876153), or use the kilometers per hour-to-Mach (sea level) page.

## Related conversions

- [Kilometers per hour to Mach (sea level)](https://tttkmbb.com/conversion/kmh-to-mach.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 Kilometers per hour](https://tttkmbb.com/conversion/meters-per-second-to-kmh.md)
- [Kilometers per hour to Meters per second](https://tttkmbb.com/conversion/kmh-to-meters-per-second.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)

## 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)