Convert Pound to Grain
Convert pounds to grains instantly. 1 pound = 7000.0010802653 grain — use the live calculator, the exact formula, a conversion table and worked examples. Also check the Grain to Pound converter for the reverse conversion.
Units explained
Pound
The pound (lb) is a unit of mass equal to exactly 0.45359237 kilogram.
From Latin 'libra pondo' (a pound by weight); the symbol lb comes from 'libra'.
The primary weight unit in the United States and informally in the UK.
The international avoirdupois pound was fixed in the 1959 yard-and-pound agreement.
Grain
The grain (gr) equals 1/7000 of an avoirdupois pound, about 64.8 milligrams.
Based on the nominal mass of a single barley grain.
Ammunition and bullet mass, archery, and historical pharmacy.
Standardized through the English avoirdupois system and retained in 1959.
Pound to Grain conversion formula
The relationship between pounds and grains:
To convert pounds to grains, multiply the value in pounds by 7000.0010802653. To reverse, multiply grains by 0.0001428571.
How to use this converter
Type a value into the calculator. The result in grains updates as you type. Tap a quick value, copy the result with one click, or use the swap arrow to jump straight to the Grain to Pound converter for the reverse direction.
Step-by-step: convert pounds to grains
- Write down the value in pounds (lb).
- Multiply that value by the factor 7000.0010802653.
- The product is the equivalent value in grains (gr).
- To reverse, multiply the grain value by 0.0001428571.
Worked examples
Example 1 — Convert 1 lb to gr:
1 × 7000.0010802653 = 7000.0010802653 gr
Example 2 — Convert 100 lb to gr:
100 × 7000.0010802653 = 700000.1080265252 gr
Real-world example — Macroscopic to microscopic
One pound equals a million grains. Optical engineers calculating coherence length compare macro-scale path lengths with micro-scale wavelength differences using exactly this conversion.
1 lb × 7000.0010802653 = 7000.0010802653 gr
Real-world example — Sub-meter precision
A 0.001-pound (1 mm) tolerance equals 1,000 grains — useful for surface-finish specs, where macro-scale dimensions are given in the larger unit but feature roughness in the smaller.
0.001 lb × 7000.0010802653 = 7.0000010803 gr
Real-world example — Macro-to-micro scale comparison
2 pounds of measurement converts to a very large number in grains — useful in materials science when comparing bulk-sample dimensions to feature-level surface specs.
2 lb × 7000.0010802653 = 14000.0021605305 gr
Pound to Grain conversion table
Standard reference values for converting pounds to grains:
| Pound [lb] | Grain [gr] |
|---|---|
| 0.01 | 70.0000108027 |
| 0.1 | 700.0001080265 |
| 1 | 7000.0010802653 |
| 2 | 14000.0021605305 |
| 3 | 21000.0032407958 |
| 4 | 28000.004321061 |
| 5 | 35000.0054013263 |
| 10 | 70000.0108026525 |
| 20 | 140000.0216053051 |
| 30 | 210000.0324079576 |
| 40 | 280000.0432106101 |
| 50 | 350000.0540132626 |
| 100 | 700000.1080265252 |
| 500 | 3500000.540132626 |
| 1000 | 7000001.0802652519 |
Frequently asked questions
How many grains is 1 pound?
How do I convert pounds to grains?
How do I convert grains back to pounds?
How many grains is 100 pounds?
Popular weight unit conversions
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)
Sources & references
Conversion factor (1 lb = 7000.0010802653 gr) verified against the following authoritative sources:
- BIPM — The International System of Units (SI Brochure 9th ed.)
Official BIPM publication defining the seven SI base units (including the meter) and the rules for their use. The global authority on units of measurement.
- NIST — Guide to the SI
US National Institute of Standards and Technology reference covering the SI base and derived units with definitions and usage rules for US technical practice.
- NIST Special Publication 811 — Guide for the Use of the International System of Units
Detailed NIST guide covering exact conversion factors between SI and US customary units along with formatting and rounding conventions.
- NIST — Refinement of values for the yard and pound (Federal Register 1959)
The treaty (signed by US
- International Hydrographic Organization — Resolution on the Nautical Mile
International authority that standardised the nautical mile at exactly 1852 m in 1929 — the value adopted worldwide for sea and air navigation.