What is Mach 1 in meters per second?

Mach 1 equals 340.29 m/s at sea level under standard atmosphere conditions (15 °C, 1 atm). This value changes with altitude and temperature.

How do I convert m/s to Mach?

Divide the speed in m/s by 340.29. For example, 680.58 m/s ÷ 340.29 = Mach 2.

Does the speed of sound change with altitude?

Yes. The speed of sound drops as altitude increases and temperature falls. At 11 km (cruise altitude) it is about 295 m/s. This tool uses the sea-level value (340.29 m/s) as the standard reference.

What is hypersonic speed in m/s?

Hypersonic is generally defined as Mach 5 or above, which equals 1,701.45 m/s at sea-level conditions.

What is the difference between subsonic, transonic, and supersonic?

Subsonic is below Mach 1 (< 340.29 m/s), transonic is roughly Mach 0.8–1.2, supersonic is Mach 1.2–5, and hypersonic is above Mach 5.

Meters per Second to Mach Converter

Name: Meters per Second to Mach Converter
Availability: InStock
Author: Nham Vu

Enter a speed in meters per second and instantly get the equivalent Mach number based on the speed of sound at sea level (340.29 m/s).

Speed to Mach Converter

Meters per Second (m/s)

Mach Number

Reverse: Mach → m/s

Mach Number

Meters per Second (m/s)

Reference Speeds

Description	m/s	Mach

Formula: Mach = m/s ÷ 340.29
Reverse: m/s = Mach × 340.29
Speed of sound at sea level, 15 °C (ISA standard).

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Summary

Enter a speed in meters per second and instantly get the equivalent Mach number based on the speed of sound at sea level (340.29 m/s).

How it works

Enter a speed in the m/s field.
The tool divides the value by 340.29 (speed of sound at sea level, 15 °C).
The Mach number result appears instantly.
Use the reverse field to convert a Mach number back to m/s.
Check the reference table for well-known speed benchmarks.

Use cases

Determine whether an aircraft or projectile is subsonic, transonic, supersonic, or hypersonic.
Convert wind-tunnel test speeds from m/s to Mach for reporting.
Cross-check aerospace engineering calculations that mix SI and Mach notation.
Estimate the Mach number of a bullet or rocket at a given speed.
Teach or study the relationship between speed and the sound barrier.

Frequently Asked Questions

Last updated: 2026-07-23 · Reviewed by Nham Vu