Quantity Converter

Convert between 38+ units across 5 categories: length, mass, volume, area, and speed. SI and imperial units with full cross-reference tables.

Quantity Converter

Foot (ft)
3.280840
Converted from Meter (m)
Millimeter (mm)
1,000.000000
1 Meter (m)
Centimeter (cm)
100.000000
1 Meter (m)
Kilometer (km)
0.001000
1 Meter (m)
Inch (in)
39.370079
1 Meter (m)
Foot (ft)
3.280840
1 Meter (m)
Yard (yd)
1.093613
1 Meter (m)

All Length Units

UnitValueFactor (to SI base)
Millimeter (mm)1,000.0000000.001
Centimeter (cm)100.0000000.01
Meter (m)1.0000001
Kilometer (km)0.0010001000
Inch (in)39.3700790.0254
Foot (ft)3.2808400.3048
Yard (yd)1.0936130.9144
Mile (mi)0.0006211609.344

Category Overview

CategoryUnitsSI Base
Length8Meter (m)
Mass8Gram (g)
Volume8Liter (L)
Area8Square meter (m²)
Speed6m/s
Common Equivalences
  • 1 mile = 1.609344 km = 5,280 feet
  • 1 kilogram = 2.20462 pounds
  • 1 liter = 33.814 fl oz = 4.227 cups
  • 1 acre = 43,560 ft² = 4,046.86 m²
  • 1 knot = 1.852 km/h = 1.15078 mph
  • Mach 1 ≈ 343 m/s = 1,235 km/h (at sea level, 15 °C)
Planning notes, formulas, and examples

About the Quantity Converter

This all-in-one quantity converter covers five measurement categories — length, mass, volume, area, and speed — with 38+ units spanning both SI/metric and US customary/imperial systems. Instead of searching for five separate converters, you can switch categories with a single dropdown and convert between any pair of units in that category.

Every conversion goes through the SI base unit (meter for length, gram for mass, liter for volume, square meter for area, meters per second for speed), so the factors are transparent and auditable. The full cross-reference table shows all unit values simultaneously, and the category overview lets you see the complete scope of supported units at a glance.

Whether you're a student working through physics homework, a traveler converting between metric and imperial, or an engineer switching between unit systems, this converter saves time by putting dozens of conversions behind a single interface with swap, preset, and batch capabilities.

When This Page Helps

Instead of five separate converters, this converter puts length, mass, volume, area, and speed conversions behind a single interface. Swap units, see all equivalents at once, and use the reference tables — all without navigating away. Use it when you need quick, auditable unit changes across metric and imperial systems without switching tools.

How to Use the Inputs

  1. Select a measurement category (length, mass, volume, area, or speed).
  2. Choose your "From" and "To" units from the dropdowns.
  3. Enter the value to convert.
  4. Use the Swap button to reverse the conversion direction.
  5. Read the primary result and all equivalent unit values in the output cards.
  6. Consult the full conversion table for all units in the category.
  7. Expand the common equivalences section for useful reference facts.
Formula used
All conversions use a base SI unit: result = value × (from_factor ÷ to_factor) Base units: meter (length), gram (mass), liter (volume), m² (area), m/s (speed)

Example Calculation

Result: 8.04672 km

5 miles × 1,609.344 m/mile ÷ 1,000 m/km = 8.04672 km.

Tips & Best Practices

  • Use the Swap button instead of re-selecting units when you need to reverse a conversion.
  • The cross-reference table updates live — use it to compare multiple units at once.
  • For cooking, the volume category includes teaspoons, tablespoons, cups, fluid ounces, and gallons.
  • Knots are nautical miles per hour — used in aviation and maritime navigation.
  • When converting area, remember that a factor of 1,000 in length becomes 1,000,000 in area (squared).

Metric vs Imperial

The metric system (SI) is based on powers of 10: milli- (10⁻³), centi- (10⁻²), kilo- (10³). The imperial/US customary system uses inconsistent factors: 12 inches per foot, 3 feet per yard, 5,280 feet per mile. Metric is used globally except in the US, Myanmar, and Liberia for everyday measurements.

Speed Context

| Speed | Context | |---|---| | 1.4 m/s (5 km/h) | Walking pace | | 12.5 m/s (45 km/h) | City driving | | 28 m/s (100 km/h) | Highway driving | | 70 m/s (252 km/h) | High-speed train | | 343 m/s (1,235 km/h) | Speed of sound (Mach 1) | | 11,186 m/s | Earth escape velocity |

Volume Confusion

US fluid ounces, cups, and gallons differ from imperial (UK) volumes. The US cup is 236.588 mL; the UK cup is 284.131 mL. This converter uses US customary units — if you need UK imperial, apply the appropriate correction factor.

Sources & Methodology

Last updated:

Frequently Asked Questions

  • 5,280 feet = 1 mile = 1,760 yards = 1,609.344 meters.