Weight conversion

Pounds to Kilograms conversion

Convert pounds (lb) to kilograms (kg). Exact avoirdupois factor: 1 lb = 0.45359237 kg. Free online tool — no sign-up. Runs locally in your browser.

Instant result

Result

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Inputs —

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Formulas

Core equations used by this converter.

lb → kgkg = lb × 0.45359237

Exact factor1 lb = 0.45359237 kg

kg → lblb = kg × 2.20462262185

iLinear conversion using factor 0.45359237. Prefer the exact factor over rounded multipliers when precision matters.

How to use

Choose lb → kg or kg → lb

Use the tabs to switch direction. Forward mode needs pounds; reverse uses the opposite unit.

Enter the value

Type a non-negative value in the active unit field.

Convert and read the result

Use Convert or let the result update automatically.

Example conversions

Common values with formula and result.

10 lb to kilograms

10 × 0.45359237 = 4.5359237 kg ≈ 4.536 kg

4.5359237 kg ≈ 4.536 kg

154 lb to kilograms (typical adult weight)

154 × 0.45359237 ≈ 69.853 kg

200 lb to kilograms

200 × 0.45359237 = 90.718474 kg ≈ 90.718 kg

90.718474 kg ≈ 90.718 kg

Reverse check: 4.536 kg → lb

4.536 × 2.20462262185 ≈ 10.00 lb

Pounds to Kilograms conversion specification

Version 1.1.0 · Engine tested

Calculation status

Engine tested 4 published cases
Named expert review Not performed
Calculation version 1.1.0

Review policy

Definition: Pounds (lb) converts to kg using a fixed linear factor. Convert pounds (lb) to kilograms (kg). Exact avoirdupois factor: 1 lb = 0.45359237 kg. Formula, body-weight examples, and lb↔kg chart.
What it calculates: Value between lb and kg. Switch direction with the converter tabs.
Inputs: Pounds (lb) or reverse unit (kg)
Outputs: Converted value in kg or lb
Formula: kg = lb × 0.45359237 · 1 lb = 0.45359237 kg
Pounds to kilograms conversion table: Pounds (lb) Kilograms (kg)
1 lb 0.454 kg
5 lb 2.268 kg
10 lb 4.536 kg
50 lb 22.680 kg
100 lb 45.359 kg
120 lb 54.431 kg
140 lb 63.503 kg
150 lb 68.039 kg
160 lb 72.575 kg
180 lb 81.647 kg
200 lb 90.718 kg
220 lb 99.790 kg
Assumptions: Conversion runs locally in the browser; values are not uploaded.
Uses the standard factor/definition for these units.
Units: lb → kg
kg → lb
Boundary conditions: Empty or non-numeric input yields no valid result.
Non-negative values are expected for physical quantities.
Example: 1 lb → 0.453592 kg
Validation cases: 1 lb → 0.45359237 kg
10 lb → 4.5359237 kg
50 lb → 22.679619 kg
100 lb → 45.359237 kg
Sources: SI / international unit definitions where applicable
CalculatorX conversion factors (local runtime)
Calculation version: 1.1.0

Pounds (lb)	Kilograms (kg)
1 lb	0.454 kg
5 lb	2.268 kg
10 lb	4.536 kg
50 lb	22.680 kg
100 lb	45.359 kg
120 lb	54.431 kg
140 lb	63.503 kg
150 lb	68.039 kg
160 lb	72.575 kg
180 lb	81.647 kg
200 lb	90.718 kg
220 lb	99.790 kg

Background

Interpretation and common distinctions.

Use the converter tabs to switch direction when available. Results for Pounds to Kilograms conversion update locally in your browser.

Frequently asked questions

Key distinctions behind the conversion.

How many kilograms in 1 lb?

Exactly **0.45359237 kg**.

Is this the same as stone or troy pound?

No. Everyday body weight and groceries use the **avoirdupois** pound. Stone: 1 st = 14 lb. Troy pounds are for precious metals — different definition.

lb to kg vs kg to lb?

- lb → kg: multiply by 0.45359237 - kg → lb: multiply by 2.20462262185 See [kilograms to pounds](/convert/weight/kg-to-pound).

Why do some charts say 0.45?

0.45 is a rounded estimate. Prefer 0.45359237 when accuracy matters.