# Archery Unit Converter

> Convert archery units instantly: grains to grams, fps to m/s, ft-lbs to joules, GPI to g/m, draw weight lb to kg, inches to cm, and momentum units.

Canonical page: https://archeryprotools.com/calculators/archery-unit-converter (the interactive calculator runs on that page)

Arrow specs, bow ratings, and hunting regulations mix imperial and metric units. Convert grains, grams, feet per second, meters per second, foot-pounds, joules, GPI, and draw weight in one place, with every result shown at once.

## 🎯 Archery Unit Converter

Enter your values below. Results update as you type.

Converted Values

All units in the selected category are shown below.

**Exact factors used:**

1 gram = 15.4324 grains · 1 m/s = 3.28084 fps · 1 joule = 0.73756 ft-lb

1 g/m = 0.39198 GPI · 1 kg = 2.20462 lb · 1 kg·m/s = 0.22481 slug·ft/s

## 📊 Common Archery Conversions

Quick reference values archers look up most often.

| Imperial | Metric | Where you see it |
| --- | --- | --- |
| 100 grains | 6.48 g | Field points and broadheads |
| 425 grains | 27.5 g | Typical whitetail hunting arrow |
| 9.0 GPI | 23.0 g/m | Mid-weight hunting shaft |
| 300 fps | 91.4 m/s | Fast compound arrow speed |
| 40 ft-lb | 54.2 J | Common deer energy guideline |
| 65 ft-lb | 88.1 J | Common elk energy guideline |
| 50 lb draw | 22.7 kg | Hunting draw weight minimums |
| 29 in draw | 73.7 cm | Average adult draw length |

## 📘 When You Need to Convert

- **European arrow specs.** Many shaft makers list weight in g/m rather than GPI. Convert before using our [arrow weight calculator](https://archeryprotools.com/calculators/arrow-weight-calculator).
- **Hunting regulations.** Several countries set minimum arrow energy in joules and minimum arrow mass in grams instead of ft-lb and grains.
- **Chronograph settings.** Some chronographs read in m/s. Convert to fps to compare against IBO speed ratings.
- **Component scales.** Kitchen and jewelry scales often read grams. Multiply by 15.43 to get grains.

## ❓ Frequently Asked Questions

**How many grains are in a gram?**

One gram equals 15.4324 grains. A 100-grain broadhead weighs about 6.48 grams, and a 425-grain arrow weighs about 27.5 grams.

**How do I convert fps to m/s?**

Divide feet per second by 3.28084. An arrow at 280 fps is traveling about 85.3 m/s.

**How do I convert ft-lbs to joules?**

Multiply foot-pounds by 1.35582. A 60 ft-lb arrow carries about 81.3 joules of kinetic energy.

**How do I convert GPI to grams per meter?**

Multiply grains per inch by 2.5512. A 9.0 GPI shaft weighs about 23.0 g/m.

**Is a grain the same as a gram?**

No. A grain is much smaller: one gram is more than 15 grains. Mixing them up is one of the most common arrow-build mistakes.

## 🧮 Related Calculators

Calculator results are planning estimates. Always confirm your setup with chronograph readings and real shooting.