Arrow Size Calculator
Enter your draw length, your bow's draw weight and the point weight. The calculator gives the arrow length, a starting spine from a simplified compound chart and the total arrow weight to aim for in grains.
- Arrow length
- Spine
- Arrow weight
This uses a simplified compound bow chart. Always check the arrow maker's own chart.
Arrows are cut about 1 in longer than your draw length. A 28 in draw takes 29 in arrows. At 60 lb with 100 grain points, a simplified chart suggests a 300 spine for that length. Aim for about 6 grains per pound of draw weight, so 360 grains in total.
Arrow spine chart
Simplified compound, 100 grain points. Search for a draw weight.
| Draw weight (lb) | Spine | Arrow weight (gr) |
|---|---|---|
| 30 | 600 | 180 |
| 35 | 600 | 210 |
| 40 | 500 | 240 |
| 45 | 500 | 270 |
| 50 | 400 | 300 |
| 55 | 400 | 330 |
| 60 | 340 | 360 |
| 65 | 340 | 390 |
| 70 | 300 | 420 |
| 75 | 300 | 450 |
Spine at 28 in arrows.
Draw length and arrow
60 lb bow, 100 grain points. Slide the draw length.
The arrow is drawn to length with its spine.
How to size arrows
Bow to arrow. Step through it.
Draw length
Measure.
Shoot a bare shaft beside fletched arrows to see if the spine is right.
Light, medium or heavy arrows
Arrow weights. Compare them.
5 gr per lb.
6 to 7 gr per lb.
8 gr per lb and up.
Never shoot an arrow lighter than 5 grains per pound. It can damage the bow.
Before you shoot
Arrow checks. Tick each item.
Tick each item as you go.
Check each arrow for cracks by flexing it gently before shooting.
What you get
Arrow sizing. Each tile explains one result.
Inches.
To try.
Grains.
Minimum.
Tip.
A stiffer spine number is a lower number. 300 is stiffer than 400.
Frequently Asked Questions
No question matches that search.
How long should my arrows be?
About an inch longer than your draw length.
What spine arrow do I need?
It depends on draw weight, arrow length and point weight. Check the maker's chart.
What does arrow spine mean?
How stiff the arrow is. A lower number is stiffer.
How heavy should my arrows be?
About five to eight grains per pound of draw weight.
Does point weight change spine?
Yes. Heavier points make an arrow act weaker.
What arrow weight for hunting?
At least about six grains per pound of draw weight.
Can arrows be too short?
Yes. Short arrows can fall off the rest and are dangerous.
Arrows that fly true
Match the length, spine and weight to your bow, and every arrow leaves the string straight and quiet.
More size calculators
Each one has its own calculator, worked examples and answers to common questions.