# Geschwindigkeitsumrechner

> Rechnen Sie mph in km/h, km/h in mph, m/s und Knoten mit exakten Faktoren um; außerdem ft/s, Mach auf Meereshöhe und Lichtgeschwindigkeit.

Interaktive Version: https://www.calcopenly.com/de/conversion/speed-converter
Thema: Einheitenumrechner

Each speed unit is a fixed number of metres per second. The road and sea units are exact: a mile per hour is 0.44704 m/s because the mile is 1,609.344 m, a kilometre per hour is 1/3.6 m/s, and a knot, one nautical mile per hour, is 1,852/3,600 m/s.

The default converts 60 mph to 96.56064 km/h, the figure a UK or US driver needs on metric roads. Sailors and pilots work in knots, and 1 knot is exactly 1.852 km/h.

Mach is fixed here at 340.294 m/s, the speed of sound in the International Standard Atmosphere at sea level and 15 °C, and results that use it are marked approximate because the real speed of sound falls with temperature. The speed of light is exactly 299,792,458 m/s by definition.

## Eingaben

- **Wert**: Eine Zahl in der Ausgangseinheit oder mit eigener Einheitenangabe
- **Von** (Optionen: metre per second (m/s), kilometre per hour (km/h), mile per hour (mph), knot (kn), foot per second (ft/s), kilometre per second (km/s), Mach (sea level) (Ma), speed of light (c))
- **Nach** (Optionen: metre per second (m/s), kilometre per hour (km/h), mile per hour (mph), knot (kn), foot per second (ft/s), kilometre per second (km/s), Mach (sea level) (Ma), speed of light (c))

## Ergebnisse

- Umgerechneter Wert — Hauptergebnis
- Umrechnung
- Umrechnungsfaktor
- Genauigkeit

## Formel

$$
\begin{gathered} x_{\text{to}} = x_{\text{from}} \times \dfrac{f_{\text{from}}}{f_{\text{to}}} \\ f = \text{one unit expressed in } \text{m/s} \end{gathered}
$$

## Durchgerechnete Beispiele

### 60 mph in km/h

- Wert: 60 mph
- Von: mile per hour (mph)
- Nach: kilometre per hour (km/h)
- **Umgerechneter Wert: 96.56064 km/h**
- **Genauigkeit: Exakt**
- Prüfquelle: 60 × 1609.344 m / 1000 = 96.56064 km/h (1 mi = 1609.344 m, NIST HB 44)

### 1 knot in km/h

- Wert: 1 kn
- Von: knot (kn)
- Nach: kilometre per hour (km/h)
- **Umgerechneter Wert: 1.852 km/h**
- Prüfquelle: 1 knot = 1 nautical mile per hour = 1852 m/h (NIST SP 811 App. B)

### 100 km/h in m/s

- Wert: 100 km/h
- Von: kilometre per hour (km/h)
- Nach: metre per second (m/s)
- **Umgerechneter Wert: 27.7777777778 m/s**
- **Genauigkeit: Exakte Definitionen, periodische Dezimalzahl**
- Prüfquelle: 100000 m / 3600 s = 250/9 (Python 3.8 fractions from the legal definitions)

### Speed of light in km/s

- Wert: 1 c
- Von: speed of light (c)
- Nach: kilometre per second (km/s)
- **Umgerechneter Wert: 299,792.458 km/s**
- Prüfquelle: c = 299,792,458 m/s exactly (SI definition of the metre)

### Mach 1 at sea level (approximate)

- Wert: 1 Ma
- Von: Mach (sea level) (Ma)
- Nach: kilometre per hour (km/h)
- **Umgerechneter Wert: 1,225.0584 km/h**
- **Genauigkeit: Näherungswert**
- Prüfquelle: 340.294 m/s (ISA sea level, 15 °C) × 3.6 = 1225.0584 km/h

## Fragen

### How do I convert mph to km/h?

Multiply by 1.609344: 60 mph × 1.609344 = 96.56064 km/h, and 70 mph is 112.65 km/h. The factor is exact because a mile is exactly 1,609.344 m. Multiplying by 1.6 is a mental shortcut that comes out 0.6% low; to go from km/h to mph, multiply by 0.621371.

### How do I convert km/h to m/s?

Divide by 3.6, because an hour has 3,600 seconds and a kilometre 1,000 metres. 100 km/h is 27.78 m/s and 36 km/h is exactly 10 m/s. Multiply by 3.6 to go back: a sprinter at 10 m/s is running 36 km/h, or 22.37 mph.

### What is a knot in mph and km/h?

One knot is exactly 1.852 km/h, about 1.15078 mph or 0.514444 m/s. It is one nautical mile (1,852 m) per hour, the speed unit of shipping and aviation, so a 30-knot wind is 55.56 km/h or 34.52 mph.

### How fast is Mach 1?

In the International Standard Atmosphere at sea level (15 °C) it is 340.294 m/s, which is 1,225.06 km/h or 761.22 mph, the value this converter uses. The speed of sound depends on air temperature, so at 11 km altitude, where the standard atmosphere is −56.5 °C, Mach 1 is about 295 m/s or 1,062 km/h.

### Why is the speed of light an exact number?

Because the metre is defined from it. Since 1983 the metre has been the distance light travels in vacuum in 1/299,792,458 of a second, which fixes c at exactly 299,792,458 m/s, or 1,079,252,848.8 km/h. Converting c into any unit here is therefore exact.

### Wie genau arbeitet „Geschwindigkeitsumrechner“?

Die Genauigkeit hängt von Ihren Eingaben und den Annahmen der Methode ab. Die Dezimalrechnung nutzt 50 signifikante Stellen, doch Schätzungen, numerische Verfahren und Quelldaten können ungenauer sein. Die angezeigte Rundung beseitigt diese Grenzen nicht. Anhand unabhängiger Quellen geprüfte Rechenbeispiele: 5. Beispielsweise wird „60 mph in km/h“ anhand von 60 × 1609.344 m / 1000 = 96.56064 km/h (1 mi = 1609.344 m, NIST HB 44) geprüft.

### Woher stammt die Methode?

NIST SP 811 (2008), Guide for the Use of the SI, Appendix B — conversion factors; NIST Handbook 44, Appendix C — General tables of units of measurement.

## Quellen

- [NIST SP 811 (2008), Guide for the Use of the SI, Appendix B — conversion factors](https://www.nist.gov/pml/special-publication-811)
- [NIST Handbook 44, Appendix C — General tables of units of measurement](https://www.nist.gov/pml/owm/nist-handbook-44-current-edition)