What "IBO speed" actually means

IBO speed is the advertised performance number on every compound-bow spec sheet. It comes from a test protocol defined by the International Bowhunting Organization: 70 lb peak draw weight, 30 inches of draw length, a 350-grain arrow, the string carrying no peep and no D-loop (a single nock set and that's it), and the cam at maximum let-off. The bow is shot through a chronograph and the published IBO is the speed of that arrow leaving the bow.

The point of the standard is comparison. If two manufacturers both publish 348 IBO, you should be looking at two bows that perform identically at the same input conditions. In practice, that's not what the chronographs say.

ATA speed is the same idea with slightly different numbers — 70 lb, 30", 350 gr — published by the Archery Trade Association. Most US manufacturers publish IBO; a few publish ATA or both. They're directly comparable for hunting compounds.

Three things create the gap between the printed spec and what an independent chronograph reads. The first two are unavoidable physics; the third is where honesty comes in.

The peep + D-loop tax (~5–7 fps)

The IBO spec calls for a bare string. Real hunting strings carry a peep sight, a D-loop, and at minimum a brass nock set. Those accessories add roughly 12–18 grains of mass near the arrow's launch point. That extra mass costs about 5–7 fps off the bare-string IBO number — a real tax that applies to every bow, not a manufacturer choice.

This is why we treat any measured-at-IBO result within 7 fps of advertised as honest. The bow probably did hit its number on a bare string in the manufacturer's test rig; you're just measuring it in shooting trim.

Sub-spec test conditions (~10 fps per inch of draw)

Most independent reviewers shoot at their actual draw length, which is usually 27–29 inches, not 30. Each inch under spec costs ~10 fps. A reviewer at 28.5" shooting an IBO-348 bow will read about 333 fps — completely expected and not a sign of dishonesty. The fix is to extrapolate back: add ~10 fps per inch of draw length the reviewer was short, and subtract ~1 fps for every 3 grains the test arrow was lighter than 350.

On the ranking page we only count measurements taken at (or within rounding distance of) full IBO spec toward a brand's mean. Sub-spec setups appear in the per-bow tables for context but are tagged separately so they don't dilute the comparison.

Aggressive published numbers

This is the only one that's a brand choice. Some manufacturers test under conditions that are technically out of IBO spec — extra-light arrows, 80 lb peak weight, letoff settings on the high end — and round up. Others test honestly but publish the round-number IBO that the marketing team wanted, not the one the chronograph actually showed. The brands consistently coming in 12–18 fps under IBO at the chronograph aren't all testing the same way. Some of them just print what sells.

A 5 fps gap is unavoidable physics. A 15 fps gap is a choice.

The interactive ranking at /field-reports/ibo-honesty sorts every active US compound brand by the average gap between advertised IBO and what an independent chronograph measured at IBO spec. The number we report (Δ) is signed: -5 means the bow shot 5 fps slower than advertised.

The verdict bands

• Honest — Δ ≥ −7 fps. Inside the peep+D-loop tolerance. The brand is publishing numbers that match physics.
• Borderline — Δ between −7 and −10 fps. Worse than the peep tax can fully explain; either the brand pads slightly or has unusual cam efficiency that doesn't translate.
• Aggressive — Δ worse than −10 fps. The brand is publishing numbers that physics doesn't reach. Sometimes by a lot.
• Improving / Oscillating — labels applied when the brand has enough years of data to show a directional trend (Mathews has steadily closed its gap; Prime swings between aggressive and borderline year over year).

What "n" means

The n column is the count of independent at-IBO measurements that fed into the brand mean. A brand with n=2 is a thinner read than n=8 — one outlier hits harder. We list every individual measurement in the per-brand dossier so you can see what's driving the average.

The industry chart

The "industry, year by year" chart shows the median Δ across all measured flagships in each year. 2024 was unusually bad — the median sat near −13. 2025 recovered to about −7 (the honest threshold). The chart is the single best answer to "is the industry getting more or less honest over time?" — currently the answer is "depends entirely on the year".

Not every datapoint in the dataset is the same quality. The brand ranking treats them all equally for the mean, but the per-bow table tags each row with its evidence tier so you can read past it.

Verified video screenshot

The strongest tier. The Cooney annual flagship shootouts (YouTube, 2022–2025) are the most-cited at-IBO data source in the industry. We pulled video screenshots directly so the chronograph numbers don't depend on a search-engine snippet that may have transcribed wrong. Roughly 30 of the dataset's at-IBO points are screenshot-verified.

Print-review chronograph

Outdoor Life, Field & Stream, Petersen's Bowhunting and similar publications all chronograph their review bows. Their numbers are usually trustworthy, but they often test at the reviewer's draw length, not 30" — so the raw measurement isn't directly at-IBO and gets tagged "near" or extrapolated.

Forum-reported / owner chronograph

ArcheryTalk and Rokslide owner threads contribute the long tail of measurements. These are useful as corroboration but suspect on their own — the user's chronograph hardware is often unknown, the test conditions casual, and the measurement is one or two shots not a series. We weight them lower implicitly by how often they corroborate or contradict the verified tier.

Snippet-only / unverified

A small number of rows came from search summarizers that paraphrased a chronograph result without us being able to verify the underlying source. These are flagged in the disclaimer on the ranking page. Treat them as guidance, not authority.

The ranking is a transparency signal, not a quality signal. A −15 fps brand can still build the best hunting bow you'll ever own. The number tells you how to read the rest of the spec sheet, not which bow to buy.

Calibrate the rest of the catalog claims

If a brand publishes 348 IBO and chronographs at 333, the published brace height, let-off, and vibration claims should be read with the same skepticism. Numbers are usually optimistic the same way across the spec sheet.

Plan your tape and arrow against measured speed

Sight tape calibration and spine chart selection both take speed as input. Always feed them your chronographed speed out of your bow with your arrow, not the IBO spec. A −15 fps brand's spec sheet sets you up to under-spine your arrow and over-shoot your sight tape if you take it literally. See the sight tape guide and the arrow setup guide for how each is sensitive to actual speed.

Don't comparison-shop on IBO alone

Two bows with the same IBO can perform very differently. A bow advertised at 340 IBO that chronographs at 338 is a faster real-world bow than one advertised at 350 that chronographs at 332. The best speed comparison is the chronograph result at your draw length, with your arrow.

Not every chronograph reads the same. Two units worth calling out:

Garmin Xero — the trusted user-grade unit

The Xero is a Doppler radar chronograph designed for archery. Multiple shop owners cross-check it against LabRadar and ProChrono, and it's the chronograph Outdoor Life and similar publications switched to for their compound testing. Treat any Xero number as authoritative within ±2 fps.

Athlon Rangecraft — reads consistently high

The Athlon Rangecraft is a popular budget Doppler unit marketed at archers. Multiple Rokslide threads document it reading 10–15 fps high vs reference chronographs at compound speeds — likely the sampling-rate or trigger-threshold logic was tuned for rifle ballistics, not arrow speeds. We discount Athlon-only datapoints unless an independent unit corroborated.

Owner-forum chronograph results without an identified unit carry ±10–15 fps measurement noise. They're useful in aggregate (when multiple owners report similar numbers, the central tendency is real); they're not useful as a single point.

• Comparing your home-chronograph reading to the spec sheet at face value. Your draw length is probably 28–29", your string has a peep and a D-loop, and your chronograph may have ±10 fps noise. Off-the-shelf you should expect to read roughly 15–20 fps under the spec — that's not a brand problem.
• Treating advertised IBO as the speed to feed into a sight tape. The tape should be calibrated against the chronographed speed of your arrow out of your bow, not the spec.
• Picking arrow spine off a chart using the spec speed for an aggressive brand. Your arrows will be under-spined for the actual energy the bow delivers.
• Comparing two brands strictly on advertised IBO. The one publishing 350 may chronograph slower than the one publishing 340. Use the ranking to calibrate.
• Reading a single chronograph review as the truth. Variance in test conditions, hardware, and arrow selection means one bow can read across a 10 fps range across reviews. The mean of multiple independent at-IBO results is more trustworthy than any single one.
• Assuming the brand's number is right and the reviewer's chronograph is wrong. Doppler units (Xero, LabRadar) are accurate to within 1–2 fps. The disagreement is usually in the brand's test conditions, not in the field measurement.

What does IBO speed mean?

IBO is a published-spec speed measured under conditions defined by the International Bowhunting Organization: 70 lb peak draw weight, 30" draw length, 350 gr arrow, no peep or D-loop on the string, max let-off. Manufacturers test their bows on a chronograph at those exact conditions and print the result on the spec sheet. It's an apples-to-apples number across brands — but only if the brand actually tested at those conditions and reported honestly.

Why is the chronograph almost always slower than the advertised IBO speed?

Two real-world reasons and one questionable one. (1) Real strings carry a peep, a D-loop, and a minimum nock set. Those accessories add ~5–7 fps of mass to the string and slow the arrow vs the bare-string IBO test. That tax is unavoidable. (2) Most chronograph reviewers test at the archer's draw length, not at 30" — and every inch under 30" costs ~10 fps. (3) Some manufacturers publish numbers measured at conditions IBO doesn't allow (extra-light arrows, 80 lb test bows) or rounded aggressively. The first two are not "lies"; the third is.

How much under-IBO is "honest"?

We treat anything within 7 fps of advertised — when measured at IBO spec — as honest. That tolerance covers the peep + D-loop tax plus normal chronograph variance. At 7–10 fps under, we call it borderline; worse than 10 fps under, we call it aggressive. The full ranking lives at /field-reports/ibo-honesty.

Does a slower-than-advertised bow shoot worse?

Not directly. A 5 fps gap at the chronograph is roughly half an inch of drop at 40 yards — well inside group size. What it tells you is more important: the brand publishes optimistic numbers, so cross-shop their other claims (stack, vibration, shootability) skeptically. Brands with tight Δ tend to be more conservative across the spec sheet.

Should I avoid brands with bad IBO honesty scores?

No — the ranking is a transparency signal, not a quality signal. A bow that's -15 fps under IBO can still be the best-shooting hunting bow you'll own. Use the ranking to calibrate your expectations: if the spec sheet says 348 and the brand averages -15, plan your sight tape for 333 fps, not 348. The miss only happens when you trust the printed number to design your arrow, sight, or trajectory.

Why don't reviewers test at full IBO spec more often?

Because hunters draw 27–29 inches, not 30. Reviewers measure speed under the conditions readers actually shoot, which is the right call for buyer education but useless for brand-honesty comparison. We re-extrapolate sub-IBO measurements back to spec using ±10 fps per inch and +1 fps per 3 gr of arrow weight, but we tag those rows as "extrapolated" and weight verified at-IBO measurements more heavily.

Is the Athlon Rangecraft chronograph reliable?

Not for archery. Multiple Rokslide and ArcheryTalk threads document Athlon reading 10–15 fps high at compound speeds — likely a sampling-rate or trigger-threshold issue tuned for rifle ballistics. The Garmin Xero is the consensus trusted unit at the user-grade tier; ProChrono Digital and LabRadar are also fine. We discount any datapoint that came from an Athlon unless an independent unit corroborated it.

Are the rankings comparing bows fairly across years?

Yes — the comparison is always between the brand's printed IBO spec for that bow and the chronographed result, not against any external speed target. A 2018 bow advertised at 340 IBO and measuring 335 is honest; a 2025 bow advertised at 350 IBO and measuring 335 is aggressive. Year-over-year, you can see the industry-wide median Δ trending — see the 'industry, year by year' chart on the ranking page.

Why aren't Mission, Diamond, Gearhead, New Breed, or Kinetic ranked?

We couldn't find independent at-IBO chronograph data for any of them. The spec-sheet number exists but no review or shootout has measured them under controlled conditions we trust. Absence of data isn't the same as a bad result — it just means we can't grade them. Those brands are listed separately on the ranking page.

How does this affect picking arrows or making a sight tape?

Sight tape: never use the IBO spec speed as input — chronograph your actual arrow out of your actual bow. The IBO honesty score gives you a prior on how far off the printed number will be, but the chrono is what your tape calibrates against. Arrow selection: spine charts use IBO speed as a proxy for kinetic energy at the bow. If your brand averages -15, treat the spec as roughly 15 fps lower than printed when reading the spine chart.

IBO speed

Published-spec speed at the IBO standard: 70 lb peak, 30" draw, 350 gr arrow, bare string, max let-off. The catalog number on every compound spec sheet.

ATA speed

Archery Trade Association equivalent of IBO. Same test conditions; different governing body.

Δ (delta)

The signed gap between measured and advertised speed at IBO conditions. −5 means 5 fps slower than advertised.

At IBO spec

A measurement taken at (or within rounding of) the IBO standard's draw weight, draw length, and arrow weight. The only condition that grounds a brand-honesty comparison.

Peep + D-loop tax

The 5–7 fps the bow loses when shot in real hunting trim vs the bare-string IBO test rig. Tax is unavoidable; we treat it as the honest tolerance.

Extrapolation

Projecting a sub-IBO chronograph result back to spec conditions using ±10 fps per inch of draw length and +1 fps per 3 grains of arrow weight reduction. Useful for filling gaps; tagged separately so it doesn't dilute the verified numbers.

Cooney shootout

Annual flagship shootout video series on YouTube (2022–2025) where multiple new bows are chronographed back-to-back at IBO conditions on the same Garmin Xero. The most-cited at-IBO source in the industry.

Garmin Xero

Doppler radar chronograph designed for archery. The trusted user-grade unit; ±2 fps against reference. Outdoor Life and similar publications standardized on it.

Athlon Rangecraft

A popular budget Doppler chronograph that reads 10–15 fps high at compound speeds. We discount Athlon-only datapoints.

Verdict band

Honest (Δ ≥ −7), borderline (−7 to −10), aggressive (worse than −10). The thresholds we use to label brands on the ranking page.

• Sight tape guide — why your chronographed speed matters more than the IBO spec for tape calibration.
• Arrow setup guide — how spine, FOC, and KE depend on real bow speed, not advertised.
• Paper tuning guide — first-pass diagnostic for clean arrow flight out of the bow.