How to Choose Arrows: Spine, Length, Weight and Spine Charts

Arrows matter as much as the bow. A beautifully set-up bow will scatter arrows that are the wrong stiffness, the wrong length or mismatched in weight, and a modest bow with well-matched arrows will group surprisingly well.

The good news is that choosing arrows comes down to three decisions in a fixed order: length, then spine, then weight and components. This guide explains each one, shows how to read a manufacturer's spine chart, and finishes with the simple test that tells you whether you got it right.

Anatomy of an arrow

Step 1: Arrow length

Arrow length is measured from the bottom of the nock groove (where the string sits) to the end of the shaft, not including the point.

The rule is simple: the arrow must be long enough that the point stays in front of the arrow rest at full draw, with a safety margin. An arrow drawn behind the rest can fall off the rest and be driven into the bow hand.

• Recurve archers usually cut arrows one to two inches longer than their draw length. Beginners often go longer, because draw length grows as form improves.
• Recurve archers with a clicker cut arrows so the point sits just ahead of the clicker blade at full draw.
• Compound archers usually cut arrows so the point sits about an inch in front of the rest at full draw, often shorter than recurve arrows of the same archer.

If you have not measured your draw length yet, start with our draw length guide. Length must be decided before spine, because a longer arrow behaves more flexibly.

Step 2: Spine

What spine actually means

Spine is an arrow's stiffness. The industry standard test, ASTM F2031, rests the shaft on two supports 28 inches apart and hangs a 1.94 lb (880 g) weight from the middle. The deflection in thousandths of an inch is the spine number.

• A 500 spine shaft bends 0.500 inch under that load.
• A 400 spine shaft bends 0.400 inch and is stiffer.
• A 340 is stiffer still.

So on carbon arrows, lower spine numbers mean stiffer arrows, which suit heavier draw weights and longer arrows.

Aluminium arrows use a four-digit size code instead, such as 1816, where the first two digits are the outside diameter in 64ths of an inch and the last two are the wall thickness in thousandths. Each size has a published spine; our Easton XX75 Jazz review shows a full size table.

Why spine matters: the archer's paradox

When a recurve archer releases the string with their fingers, the string rolls off the fingertips and moves slightly sideways. The arrow, which is resting against the side of the riser, has to bend around the bow as it leaves. This flexing is known as the archer's paradox: the arrow starts pointing slightly to one side of the target and still flies straight to it.

For that to work, the arrow has to bend the right amount. Too stiff and it is pushed off to the side; too weak and it over-flexes and flies erratically. Compound bows with centre-shot rests and release aids reduce this effect, but spine still matters because the arrow is still flexing under the force of launch.

What changes the spine you need

The spine number printed on a shaft is its static spine. How it behaves when shot, its dynamic spine, depends on all of the factors above, which is why a chart is needed.

Step 3: Read a spine chart

Every major arrow maker publishes a selection chart, as a PDF or an online selector. The details differ, but they all work the same way.

1. Find your actual draw weight at your draw length. Not the number printed on the limbs, which is measured at 28 inches. A shop can measure it with a bow scale.
2. Apply any adjustments the chart lists. For example, Easton's target chart instructions adjust the bow weight by about 3 lb for every 25 grains of point weight above or below 100 grains. Some charts also adjust for release type and string material.
3. Find your arrow length across the top of the chart.
4. Read off the spine group where your adjusted weight and arrow length meet.
5. Pick a shaft from that group in the range you want.

If you land between two sizes, Easton's guidance for recurve archers is to choose the weaker option when more than one size fits. Recurve archers can then tune with plunger tension and point weight.

Step 4: Weight, points and front-of-centre

Total arrow weight

Arrow weight is quoted in grains (7,000 grains to a pound). Shafts are listed in grains per inch (GPI), so total weight is roughly:

GPI × shaft length + point + insert + nock + fletching

Lighter arrows fly faster and flatter; heavier arrows are quieter and carry more momentum. Target archers generally favour lighter arrows for flatter trajectories at distance. Hunters often choose heavier arrows for penetration.

Compound archers must also respect their bow's minimum arrow weight. Most compound manufacturers specify one, commonly expressed as grains per pound of draw weight. Shooting an arrow lighter than the minimum can damage the bow in a similar way to a dry-fire. Check your owner's manual.

Front-of-centre (FOC)

FOC describes how far forward the balance point is. To calculate it:

1. Find the balance point of the finished arrow, measured from the bottom of the nock groove.
2. Subtract half the arrow's length.
3. Divide by the arrow's length and multiply by 100.

A forward balance helps the arrow stay point-first in flight. Heavier points increase FOC, but remember that they also make the arrow act weaker.

Step 5: Fletching and nocks

The index vane (usually a different colour) shows which way to nock the arrow. For recurve archers it normally points away from the riser.

Step 6: Straightness and consistency

Shafts are sold by straightness tolerance, for example ±0.006, ±0.003 or ±0.001 inch. More important than the number is that every arrow in your set is the same: same shaft, length, point, nock and fletching. A dozen identical mid-grade arrows will group better than a mixed set of premium ones.

Number your arrows. If one regularly lands outside the group even when you shoot well, it is probably damaged or mismatched.

Step 7: Check your choice with bare-shaft tuning

Once you have your arrows, a simple test confirms the spine is right. This is the method widely taught for recurve and traditional bows.

1. Prepare three fletched arrows and one or two identical arrows with no fletching (bare shafts).
2. From about 10 yards, shoot the fletched arrows at a spot, then the bare shaft at the same spot, with your best form.
3. Compare where the bare shaft lands relative to the fletched group.

For a right-handed finger archer:

Left-handed archers read left and right the other way round. Fix vertical errors first, then horizontal, one small change at a time. When the bare shaft groups with the fletched arrows at 10 yards, move back to 15 or 20 and check again.

Quick reference

Frequently asked questions

Can I use the arrows that came with my bow?

Package arrows are often generic. Check their length against your draw length and their spine against the chart for your draw weight. If either is wrong, replace them before they cause bad habits.

What happens if my arrows are too stiff or too weak?

They will tend to fly to one side and group poorly, and a badly mis-spined arrow can strike the riser. The bare-shaft test above shows which way you are off.

Do I need different arrows as my draw weight increases?

Usually yes. Each significant jump in draw weight moves you to a stiffer spine. Many recurve archers buy new arrows every time they change limbs.

Are carbon arrows better than aluminium?

Not automatically. Aluminium is consistent, repairable and available in very light spines for beginners and children. Carbon is lighter for its stiffness and does not bend, which helps at long distance and in hunting. Our reviews of the Easton XX75 Jazz and Gold Tip Hunter XT cover one of each.