Broadhead Weight Chart: Grains, Cut Width, Fixed vs Mechanical
One hundred grains is the standard broadhead weight and the most widely available, with 125 and 150 grains common on heavier hunting builds. Fixed heads typically cut 1 to 1-3/8 inches and mechanicals 1-1/2 to 2-1/3 inches. Every 25 grains of point weight acts roughly like adding 3 to 5 lb of draw weight to dynamic spine.
Broadhead weight is the largest single lever in an arrow build. It moves finished arrow weight, front of centre, dynamic spine and trajectory all at once, which is why swapping heads is never just a swap. This chart shows what each common grain weight does to a representative hunting arrow, along with the cut diameters you can actually buy at that weight.
Broadhead weight chart
The FOC and finished weight columns are calculated for one specific arrow so the comparison is honest: a 29 inch shaft at 8.5 grains per inch, a 12 grain aluminium insert, a 10 grain nock and 18 grains of fletching. Your arrow will differ, but the direction and rough magnitude of each change will not.
| Point weight | Typical fixed cut | Typical mechanical cut | Common use | FOC on example arrow | Finished weight | Dynamic spine shift |
|---|---|---|---|---|---|---|
| 50 gr | n/a | n/a | Small game heads, blunts, judo points | 5.7% | 337 gr | acts 8 lb stiffer |
| 75 gr | 1 to 1-1/8 in | n/a | Light draw weights, speed-focused target builds | 9.0% | 362 gr | acts 4 lb stiffer |
| 85 gr | 1 to 1-1/8 in | 1-1/2 to 2 in | Lighter setups, some crossbow and youth builds | 10.1% | 372 gr | acts 2 lb stiffer |
| 90 gr | 1 to 1-1/8 in | 1-1/2 in | Uncommon, sits between the two standards | 10.7% | 377 gr | acts 2 lb stiffer |
| 100 gr | 1 to 1-1/4 in | 1-1/2 to 2-1/3 in | The industry standard, widest model selection | 11.8% | 387 gr | reference |
| 110 gr | 1 to 1-1/4 in | 1-1/2 to 2 in | A small step up without a spine change | 12.8% | 397 gr | acts 2 lb weaker |
| 125 gr | 1-1/8 to 1-3/8 in | 1-1/2 to 2 in | The second standard, common on hunting builds | 14.2% | 412 gr | acts 4 lb weaker |
| 150 gr | 1-1/8 to 1-3/8 in | 1-1/2 to 2 in | Elk and larger game, higher FOC builds | 16.4% | 437 gr | acts 8 lb weaker |
| 175 gr | 1 to 1-3/16 in | rare | Single bevel and heavy two-blade territory | 18.4% | 462 gr | acts 12 lb weaker |
| 200 gr | 1 to 1-3/16 in | rare | Extreme FOC builds, large or heavy-boned game | 20.1% | 487 gr | acts 16 lb weaker |
| 225 gr | 1 to 1-3/16 in | n/a | Traditional and heavy-arrow specialists | 21.7% | 512 gr | acts 20 lb weaker |
| 250 gr | 1 to 1-1/4 in | n/a | Traditional builds, large plains game | 23.1% | 537 gr | acts 24 lb weaker |
| 275 gr | 1 to 1-1/4 in | n/a | Heavy traditional builds | 24.4% | 562 gr | acts 28 lb weaker |
| 300 gr | 1 to 1-1/4 in | n/a | Ultra-heavy arrows, the largest game | 25.6% | 587 gr | acts 32 lb weaker |
| 350 gr | 1 to 1-1/4 in | n/a | Specialist heavy builds, usually with a heavy insert too | 27.7% | 637 gr | acts 40 lb weaker |
Cut diameter ranges describe what is commonly available at each weight rather than any single model, and manufacturers differ. The dynamic spine column uses the common approximation of 4 lb of equivalent draw weight per 25 grains of point weight, which is the middle of the 3 to 5 lb range most sources quote.
How to read the FOC column
Front of centre is the percentage of the arrow's length by which its balance point sits forward of the physical middle. On the example arrow, a 100 grain head produces about 11.8 percent, which is comfortably inside the 10 to 15 percent band most hunting guidance recommends. Moving to 150 grains pushes it to 16.4 percent, and 200 grains reaches 20.1 percent, which crosses into what is generally called extreme FOC.
Notice that the returns diminish. The first 100 grains of point weight buys about 6 points of FOC. The next 100 buys about 8, but at the cost of 100 grains of arrow weight, a spine group and a noticeably steeper trajectory. Adding a brass insert instead is often the cheaper route to the same balance point, and it does not change the head you have already tuned around. The FOC reference chart covers the bands in detail and the FOC calculator works out your own arrow.
Fixed versus mechanical
This is the argument that never ends, largely because both sides are describing real behaviour. The table below is the honest version.
| Factor | Fixed blade | Mechanical |
|---|---|---|
| Typical cut diameter | 1 to 1-3/8 in | 1-1/2 to 2-1/3 in |
| Flight versus field points | Steers in the wind, needs a tuned bow | Very close to field points out of the box |
| Energy used on deployment | None | Some, which reduces penetration |
| Tolerance of heavy bone | Better, no moving parts to fail | Variable, depends on design and build quality |
| Tuning sensitivity | High, exposes any tuning error | Low, which is why they sell so well |
| Best suited to | Heavy arrows, larger game, lower poundage setups | Well-tuned faster bows on deer sized game |
| Failure modes | Bent or loosened blades | Premature or failed deployment |
| Legal restrictions | Rarely restricted, some states ban barbed designs | Prohibited for game mammals in some states |
| Practical cost per pack | Broadly similar | Broadly similar, replacement blades add up |
The useful framing is that a mechanical compensates for a bow you have not tuned, and a fixed head rewards one you have. If your paper tear is clean, your bare shafts group with your fletched shafts, and your arrow is properly spined, a fixed head costs you nothing and gives back reliability. If any of that is not true, a mechanical will hide the problem rather than solve it. Work through the tuning troubleshooting chart before deciding which camp you belong in.
Blade count, bevel and ferrule design
Two-blade cut-on-contact heads have the narrowest entry profile and the least resistance, which is why they dominate heavy arrow and traditional builds. Three-blade chisel tip heads are the mainstream compound choice, trading a little penetration for durability and a wider wound channel. Four-blade designs add a bleeder blade, increasing cutting surface at a further cost in penetration.
Single bevel heads sharpen on one side of each blade so the head rotates on impact. Advocates report improved performance against bone on large animals. They are almost always sold in heavier weights, 175 grains and up, which is part of why heavy point weight and single bevel designs travel together in the same builds.
Ferrule construction matters more than the marketing suggests. A head that flexes or that loosens at the blade slots will not fly consistently regardless of grain weight. Spin-test every head on the finished arrow: mounted on a shaft and rotated on a spin tester, a good head shows no wobble at the tip. Any wobble is a straightness or squareness problem to fix before you shoot it.
Matching weight to your setup
Start from what your shaft can tolerate. A 340 spine shaft at 29 inches on a 70 lb bow is comfortable with 100 to 125 grains. Push it to 175 and it is behaving like a 400, which usually shows as a weak-side tear and poor broadhead grouping. If you want 175 grains up front, buy the 300 spine shaft to begin with rather than trying to tune your way out of it. The arrow spine chart shows the shift, and the spine calculator takes point weight as an input for exactly this reason.
Then check the finished weight against the 5 grains per pound safety floor with the total arrow weight calculator. Heavier heads make this easy to clear, but a light head on a short shaft at high poundage can quietly drop under it.
Related tools and charts
- Arrow FOC calculator: see what a head swap does to your balance point
- Total arrow weight calculator: finished grains and the safety floor
- Arrow spine calculator: point weight is a required input
- FOC reference chart: what each FOC band is used for
- Kinetic energy by game chart: matching the whole system to the animal
Frequently asked questions
What broadhead weight should I use?
One hundred grains is the default and the safest starting point, because it matches the field points most bows are sighted in with and it is the weight nearly every model is offered in. Move to 125 or 150 grains if you want more front of centre and more momentum, and be prepared to drop a spine group when you do. Below 100 grains is a speed choice with real trade-offs in penetration.
Do heavier broadheads penetrate better?
Usually, for two reasons that compound. Extra point weight raises total arrow weight, which raises momentum, and it raises front of centre, which keeps the arrow driving straight when it meets resistance. The cost is trajectory and dynamic spine. A 175 grain head on a shaft chosen for 100 grains will act a full spine group weaker and often tunes badly until you change shafts.
Are mechanical or fixed broadheads better?
They optimise for different problems. Mechanicals fly like field points because the blades are stowed, so they forgive an imperfectly tuned bow and cut a wider hole. Fixed heads have no deployment to fail, hold up to heavy bone, and preserve more energy for penetration. Fixed heads demand better arrow flight to shoot well. Several states also restrict mechanicals, so check regulations before choosing.
Does broadhead weight change arrow spine?
It changes dynamic spine, which is the spine that matters. Adding mass at the very front of the arrow increases the inertia the string has to overcome, so the shaft flexes more and behaves weaker. Every 25 grains added acts roughly like adding 3 to 5 lb of draw weight. Going from a 100 to a 175 grain head is therefore similar to adding 9 to 15 lb, which is often a full spine group.
What is the minimum legal broadhead width?
Seven-eighths of an inch is the most common statutory minimum across US states, measured at the widest point and, for mechanicals, in the open position. Some states set different figures, North Dakota at three-quarters of an inch and Wyoming at one inch among them, and a few prohibit mechanical or barbed heads outright. Verify the current requirement with your state wildlife agency before the season.
Do I need to re-sight my bow when I switch broadhead weight?
Yes, and more than most archers expect. Changing point weight changes both arrow weight and dynamic spine, so the arrow leaves the bow differently and drops differently. Shoot the new setup through paper first to confirm the tune still holds, then re-establish sight marks at every distance you intend to shoot. Practise with the same head weight you hunt with, not just matching field points.
How we choose: we compare published manufacturer specifications, verified owner reviews, and pro shop guidance. We do not test gear in person. Draw weight and arrow spine affect safety, so follow your bow manufacturer's specifications and have setup work checked by a qualified pro shop.