What is Mach 1 in feet per second?

Mach 1 equals the speed of sound, which at sea level under standard conditions is approximately 1125.33 ft/s (343 m/s). The exact value varies with air temperature and altitude.

How do I convert Mach to feet per second?

Multiply the Mach number by 1125.33. For example, Mach 2 × 1125.33 = 2250.66 ft/s. This tool performs that calculation automatically.

Why does the speed of sound vary with altitude?

The speed of sound depends on air temperature, which decreases with altitude. At cruise altitude (~36,000 ft), the speed of sound drops to about 968 ft/s. This tool uses the sea-level ISA standard value of 1125.33 ft/s.

What are the Mach flight speed regimes?

Subsonic: below Mach 0.8; transonic: Mach 0.8–1.2; supersonic: Mach 1.2–5; hypersonic: above Mach 5. Commercial airliners cruise near Mach 0.85, while the SR-71 Blackbird reached about Mach 3.3.

What is the difference between ft/s and fps?

They are the same unit. "ft/s" and "fps" (feet per second) are interchangeable abbreviations used in aerodynamics, ballistics, and fluid dynamics in the US customary system.

Mach to Feet per Second Converter

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

Convert Mach number to feet per second (ft/s) instantly using the standard speed of sound at sea level (1125.33 ft/s).

Mach to ft/s Converter

Mach Number

Feet per Second (ft/s)

Reference Speeds

Click any row to load it into the converter.

Description	Mach	ft/s

Conversion Formula

ft/s = Mach × 1125.33

Mach = ft/s ÷ 1125.33

Speed of sound at sea level (ISA): 343 m/s = 1125.33 ft/s. The actual value varies with air temperature and altitude.

Summary

Convert Mach number to feet per second (ft/s) instantly using the standard speed of sound at sea level (1125.33 ft/s).

How it works

Enter a Mach number in the top field.
The tool multiplies the value by 1125.33 ft/s (speed of sound at sea level).
The equivalent speed in feet per second appears instantly along with the flight regime.
Use the ft/s field for the reverse conversion: ft/s to Mach.
Click any row in the reference table to load that speed into the converter.

Use cases

Convert aircraft or missile speeds from Mach to ft/s for aerodynamics calculations.
Translate wind-tunnel test Mach numbers to ft/s for US-customary engineering reports.
Determine whether a given Mach number is subsonic, transonic, supersonic, or hypersonic.
Convert historical speed records expressed in Mach to ft/s equivalents.
Verify manual Mach-to-ft/s calculations during aerospace or physics coursework.
Prepare speed data for presentations and reports that require ft/s instead of Mach.

Frequently Asked Questions

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