Home Arrow Weight Calculator
Arrow Weight Calculator (GPI & Components)
Calculate your total arrow weight in grains.
Essential for kinetic energy calculations and choosing hunting arrows.
Add up all components for precise weight.
💡 For compound bows, 5 grains per pound is a common IBO benchmark and appears as a minimum in BowTech manuals, but the minimum for your exact bow model is whatever its manufacturer specifies.
Example arrow weight calculation
| Component | Weight |
|---|---|
| Shaft (9.0 GPI × 29") | 261 grains |
| Point / broadhead | 125 grains |
| Nock | 10 grains |
| Fletching | 30 grains |
| Insert | 20 grains |
| Total arrow weight | 446 grains |
On a measured 60 lb compound bow, 446 grains equals about 7.4 grains per pound. That arithmetic is useful for checking a bow manual, but it does not by itself determine hunting suitability, penetration, or the correct arrow spine.
🎯 Need heavier components to increase arrow weight?
Shop heavy broadheads (150–200 gr) at Optics Planet, brass inserts on Amazon, or high-GPI arrow shafts at Optics Planet.
Understanding arrow weight
What counts toward total arrow weight?
Total arrow weight is the mass of the complete finished arrow, measured in grains (1 grain = 1/7000 of a pound). Include the shaft, point or broadhead, insert/outsert/collar, nock, fletching, wraps, and any other installed components.
GPI (grains per inch)
GPI is the shaft manufacturer's published mass for one inch of a particular shaft model and spine. Multiply GPI by the cut shaft length to estimate bare-shaft mass:
Shaft weight = GPI × cut shaft length
For example, a 9.0 GPI shaft cut to 29" weighs 261 grains before adding the point, insert, nock, fletching, wrap, or other components.
Why grains per pound matters
Grains per pound (GPP) compares finished arrow mass with actual bow draw weight:
GPP = finished arrow weight ÷ draw weight
BowTech's current customer-service guidance explains the IBO reference using 5 GPP, and multiple BowTech manuals warn against arrows below 5 GPP for the covered compound models. That does not make 5 GPP a universal minimum for every bow. Traditional-bow recommendations can be very different, and the manual for your exact model takes priority.
How to choose an arrow weight safely
1. Start with the bow manufacturer's minimum
Before optimizing speed, trajectory, or hunting performance, find the minimum finished arrow mass in the manual for your exact bow. Do not assume that a general web chart overrides the manufacturer.
2. Calculate grains per pound from your real draw weight
If a compound bow is actually set to 60 lb and the finished arrow weighs 300 grains, that is 5.0 GPP. A 450-grain arrow from the same 60 lb setup is 7.5 GPP. The calculator above performs this arithmetic when you enter draw weight.
3. Expect bow type and purpose to change the preferred mass
A speed-oriented compound target setup, a hunting compound, and a traditional bow may all use different arrow-mass strategies. For example, BowTech uses 5 GPP in its IBO compound-bow reference, while Bear Archery's traditional-bow tuning guidance from Fred Eichler recommends substantially heavier 9-10 GPP arrows for that traditional context.
4. Re-check spine whenever component mass changes
Adding front-end weight can change dynamic spine even though the static spine number printed on the shaft stays the same. Confirm substantial changes with the arrow spine calculator and the shaft manufacturer's selector.
How to get accurate component weights
Component weights vary by exact model and size, so the most reliable inputs come from the manufacturer's specification or a grain scale rather than a generic range.
- Shaft: use the published GPI for the exact shaft model and spine, or weigh the cut bare shaft.
- Point / broadhead: use the marked or measured finished weight.
- Insert, outsert, collar, or weight system: include every front component actually installed.
- Nock: weigh the exact standard or lighted nock you use.
- Fletching and wraps: include the total installed rear-component mass.
A small grain scale is useful when catalog values are unavailable or when you want to verify the finished build.
How component changes affect total arrow weight
➕ Point or broadhead
Changing from a 100-grain point to a 125-grain point adds exactly 25 grains to finished arrow mass and also moves mass forward.
🔩 Insert / outsert system
Front components add their actual measured or published mass to the finished arrow and can change FOC and dynamic spine.
📏 Shaft GPI
A 2 GPI increase adds about 58 grains to a 29" shaft before other components: 2 × 29 = 58 grains.
🪶 Rear components
Different nocks, wraps, vanes, or feathers change both total mass and balance. Use the actual installed weights when precision matters.
After a meaningful front-end change, re-check both FOC and arrow spine.
Technical sources
- BowTech Customer Service — current explanation of the 5 GPP IBO speed reference
- BowTech Reckoning Gen 2 Owner Manual (2025) — model-specific warning on arrows below 5 GPP
- Gold Tip Arrow Weight & FOC Calculator — component-based finished-weight inputs
- Bear Archery / Fred Eichler — traditional-bow tuning example using heavier GPP guidance
Arrow weight calculator FAQs
How do I calculate total arrow weight?
Add the mass of every installed component: shaft + point or broadhead + insert/outsert/collar + nock + fletching + wrap + any other hardware. If the shaft is specified in GPI, multiply GPI by cut shaft length to estimate shaft mass, then add the other components.
What is GPI in arrows?
GPI means grains per inch and describes shaft mass per inch for a specific shaft model and spine. Multiply the manufacturer's GPI by the cut shaft length to estimate bare-shaft weight. A 9.0 GPI shaft cut to 29" is 261 grains before other components are added.
What is grains per pound (GPP)?
GPP is finished arrow weight divided by actual bow draw weight. For example, a 450-grain arrow from a 60 lb bow is 7.5 GPP. Use GPP to compare your finished arrow with the safety and setup guidance in your bow's manual.
Is 5 grains per pound a universal minimum arrow weight?
No. Five GPP is a common IBO compound-bow reference and BowTech uses it as a minimum in manuals for multiple compound models, but the manufacturer of your exact bow controls its safe minimum. Traditional and specialty bows may use different guidance.
How does arrow weight affect speed?
More arrow mass generally reduces velocity from the same bow. The exact FPS change is bow-specific. BowTech has published about 1 FPS of loss per 3 grains added above the 5 GPP IBO reference for some compound systems, but that should not be treated as a universal formula for every bow.
Should I use a heavier or lighter arrow?
First stay within the bow manufacturer's arrow-mass and spine requirements. After that, choose mass based on your discipline, trajectory needs, tuning, noise, and desired energy/momentum. Total grains alone are not enough to prescribe one universal hunting or target arrow.
How do I know what my components weigh?
Use the manufacturer's specifications for the exact component or weigh the component on a grain scale. For a finished arrow, weighing the complete build is the best check that no wrap, collar, adhesive, or other small component was omitted.