Mass and Weight · Unit Converter

Convert Pound to Slug

Convert pounds to slugs instantly. 1 pound = 0.0310809502 slug — use the live calculator, the exact formula, a conversion table and worked examples. Also check the Slug to Pound converter for the reverse conversion.

Written by Sunith Babu L, Ph.D., Lead Engineer Reviewed by Dr. Ashok Kumar K, Ph.D.
Mass and Weight category 2 min read Published Last reviewed Updated

Units explained

Avoirdupois

Pound

What is a pound?

The pound (lb) is a unit of mass equal to exactly 0.45359237 kilogram.

Origin of the pound

From Latin 'libra pondo' (a pound by weight); the symbol lb comes from 'libra'.

Where it is used

The primary weight unit in the United States and informally in the UK.

When and where it was developed

The international avoirdupois pound was fixed in the 1959 yard-and-pound agreement.

Force / Engineering

Slug

What is a slug?

The slug is the mass that accelerates at 1 ft/s^2 under a force of one pound-force, about 14.59 kg.

Origin of the slug

Coined in the early 20th century for the British gravitational (engineering) system.

Where it is used

US and British engineering dynamics.

When and where it was developed

Introduced in the British gravitational system of units.

Pound to Slug conversion formula

The relationship between pounds and slugs:

1 lb = 0.0310809502 slug
1 slug = 32.1740485564 lb

To convert pounds to slugs, multiply the value in pounds by 0.0310809502. To reverse, multiply slugs by 32.1740485564.

How to use this converter

Type a value into the calculator. The result in slugs updates as you type. Tap a quick value, copy the result with one click, or use the swap arrow to jump straight to the Slug to Pound converter for the reverse direction.

Step-by-step: convert pounds to slugs

  1. Write down the value in pounds (lb).
  2. Multiply that value by the factor 0.0310809502.
  3. The product is the equivalent value in slugs (slug).
  4. To reverse, multiply the slug value by 32.1740485564.

Worked examples

Example 1 — Convert 1 lb to slug:
1 × 0.0310809502 = 0.0310809502 slug

Example 2 — Convert 100 lb to slug:
100 × 0.0310809502 = 3.1080950172 slug

Real-world example — Adult height conversion

A 1.8-pound-tall person measures a value in slugs that converts the height to the unit favoured by American forms, schools, or driver's licences. This is daily routine for anyone living between metric and imperial systems.

1.8 lb × 0.0310809502 = 0.0559457103 slug

Real-world example — Fabric purchase length

Two pounds of fabric equals a value in slugs essential for tailors and textile buyers sourcing material from international suppliers that quote in different units.

2 lb × 0.0310809502 = 0.0621619003 slug

Real-world example — Maritime depth conversion

A 10-pound sounding depth converts cleanly into slugs. Recreational divers and sailors translate between the two units whenever they read legacy charts against modern depth-sounder displays.

10 lb × 0.0310809502 = 0.3108095017 slug

Pound to Slug conversion table

Standard reference values for converting pounds to slugs:

Pound [lb]Slug [slug]
0.010.0003108095
0.10.003108095
10.0310809502
20.0621619003
30.0932428505
40.1243238007
50.1554047509
100.3108095017
200.6216190034
300.9324285051
401.2432380069
501.5540475086
1003.1080950172
50015.5404750858
100031.0809501716

Frequently asked questions

How many slugs is 1 pound?
1 pound equals 0.0310809502 slug.
How do I convert pounds to slugs?
Multiply the value in pounds by 0.0310809502 to get slugs.
How do I convert slugs back to pounds?
Multiply the value in slugs by 32.1740485564, or use the Slug to Pound converter.
How many slugs is 100 pounds?
100 pounds equals 3.1080950172 slugs, because 100 × 0.0310809502 = 3.1080950172.

Convert Pound to other weight units

Show all Pound conversions
Metric / SI (18 units)
Avoirdupois (14 units)
Troy & Apothecary (10 units)
Indian / South Asian (6 units)
Scientific / Atomic (9 units)
Astronomical (4 units)
Biblical / Ancient (14 units)
Force / Engineering (5 units)

Sources & references

Conversion factor (1 lb = 0.0310809502 slug) verified against the following authoritative sources:

Results are provided for general reference. Verify critical measurements against an authoritative standard.