Home Peep Sight Height Calculator
Peep Sight Height Calculator
Find your ideal peep sight starting position for compound bows. Based on draw length, axle-to-axle, anchor point, and release type. Includes peep size guide, rotation fixes, and full setup walkthrough.
Quick navigation: Calculator · Peep Size Guide · How to Set Your Peep · Fix Peep Rotation · FAQs
💡 This calculator provides a starting position only. Always verify with the eyes-closed method and fine-tune at the range before final serving.
Example calculation
A common hunting setup: 28" draw length, 33" ATA bow, index finger release, under-chin anchor.
| Input | Value |
|---|---|
| Draw length | 28 inches |
| Axle-to-axle | 33 inches |
| Anchor | Under chin |
| Release | Index finger / wrist strap |
| Estimated peep height | ~5.5–6.0 inches above nocking point |
This is the starting measurement before eyes-closed verification and sight alignment. Final position may shift ±0.5" based on your personal anchor and face structure.
🎯 Building your complete bow setup? Peep sight is one piece of the puzzle:
- Step 1: Draw Length Calculator — foundation of everything
- Step 2: Peep Sight Height Calculator — you are here
- Step 3: Sight Mark Calculator — dial in your pin gaps
- Step 4: Shot Angle Calculator — compensate for treestand shots
Peep sight size guide
Peep size is measured by the inside diameter of the aperture hole. Larger peeps let in more light and are faster to align; smaller peeps create a more precise aiming reference. Choose based on your primary shooting scenario.
| Size | Inside Diameter | Best For | Trade-off |
|---|---|---|---|
| 3/32" | 2.4mm | Indoor target / precision | Very dark in low light; slow to acquire |
| 1/8" | 3.2mm | Outdoor target / 3D competition | Excellent precision; limited in dim light |
| 3/16" | 4.8mm | Hunting (most popular) | Great balance of precision and light |
| 1/4" | 6.4mm | Low-light hunting / beginners | Very bright; less precise aiming circle |
| No-peep / open | — | Traditional / barebow | Fastest; no rear sight reference |
Which peep size should hunters choose?
The 3/16" peep is the overwhelming favourite for hunting. It provides a usable aiming circle around most single-pin or multi-pin sight housings, and it still transmits enough light for dawn and dusk shots — the highest-activity periods for deer and elk.
If you hunt in heavy timber where legal shooting light is tight, consider stepping up to a 1/4". If you shoot under bright range conditions or in 3D tournaments, a 1/8" gives noticeably tighter groups.
Shop peep sights: Optics Planet peep sight selection.
How to set your peep sight: step-by-step
Setting a peep sight correctly takes 15–30 minutes the first time, and much less on future bows once you understand the process. Here's the full sequence.
Step 1: Calculate your starting height
Use the calculator above to get your estimated starting position. This saves you from having to do the eyes-closed method multiple times. The calculator accounts for your bow's string angle geometry — shorter ATA bows require a higher peep on the string because the steeper string angle moves the peep down relative to your eye at full draw.
Step 2: Mark the string
Measure your calculated starting height above the top of your nocking point (or the top nock set, if using brass nock sets). Use a small piece of white tape or a pencil mark so you have a reference point before splitting the string.
Step 3: Eyes-closed verification (before serving)
Nock an arrow. Draw your bow with your eyes closed and settle into your normal anchor point. Open your eyes. Have a helper mark the string right where your dominant eye aligns with your sight housing center. Compare this mark to your calculated position. They should be within 0.25–0.5 inches of each other — if not, your anchor point may be inconsistent and worth correcting first.
Step 4: Split the string and insert the peep
This step requires a bow press if your string is heavily served. Separate the string strands at your marked location, slide the peep in, and hold it in place. Before serving, draw the bow again to confirm the position. Small adjustments now are easy; re-serving after the fact takes 10x longer.
If you are not comfortable with a bow press, take it to a pro shop. Most will install and serve a peep sight for $15–25. Incorrectly pressing a bow can damage cams and cables. Equipment: bow press options at Amazon.
Step 5: Serve the peep in
Serve over the peep tightly with serving thread, creating at least 0.5 inches of serving on each side of the peep. Some archers prefer a "floating" install — served only on the outer edges — which allows micro-adjustments. Either method works; a full serve is more permanent.
Step 6: Align to your sight at the range
Set your bow sight at your primary distance (20 or 30 yards). Draw and aim. The sight housing should appear centered inside the peep aperture. If the housing sits low in the peep, your peep is too high — move it down and re-serve. If the housing sits high, move the peep up. Make 1/8" adjustments at a time.
Step 7: Shoot and confirm
After final position is set, shoot 10–15 arrows. Your groups will tell you if the peep is truly dialed in. Consistent groups that just need the sight moved horizontally or vertically indicate a properly positioned peep. Scattered groups with peep-related inconsistency suggest a position or rotation problem.
Related: Once your peep is set, dial in your pin gaps with the Sight Mark Calculator.
How to fix peep sight rotation
Peep rotation is one of the most common compound bow frustrations. You draw, and the peep has rotated 30–90 degrees out of alignment. Here's why it happens and how to fix it permanently.
Why peeps rotate
Modern bow strings are made of parallel bundles of fiber. When the bow is pressed and the string is split to install the peep, those fibers get separated. When you draw and release, the string tries to return to its natural state — and the rotation torque in the fibers spins the peep. The severity depends on string material, string age, and how the peep was installed.
Fix 1: Add or remove string twists
This is the most reliable fix. Disconnect the string from the lower limb and add twists (or remove them) to change the string's rotational tension. The direction depends on which way the peep rotates: if it rotates clockwise at full draw, add counter-clockwise twists. Add 1–2 twists at a time, then draw and check. Most setups need 2–8 twist adjustments total.
Fix 2: Adjust cable tension
On single cam and hybrid cam bows, the cables also influence string rotation. Twisting the control cable in the opposite direction of peep rotation can correct alignment without changing string length (and therefore draw length).
Fix 3: Re-serve at a corrected angle
If twist adjustments aren't resolving the rotation, the peep can be served in at a pre-rotated angle — installed rotated 15–20 degrees opposite to its direction of drift, so that at full draw it sits perfectly square. This takes experience and is best done by a pro shop tech or experienced DIY archer.
Fix 4: Use a tube peep or angled aperture peep
Tube-style peeps connect to the bow sight via a small rubber tube that physically pulls the peep into alignment regardless of string rotation. They're reliable but add a small amount of weight and bulk. Quality hooded peeps with angled apertures self-align when the string is at full draw. Both are valid solutions if twist adjustments don't fully resolve the issue.
Note: New strings typically settle over 100–200 shots as fibers seat and stretch. If your bow is freshly re-strung, shoot it in fully before making final peep rotation corrections.
Peep height starting points by ATA length
This table shows approximate starting peep heights for a 28" draw length under-chin anchor at standard D-loop length. Use it as a cross-reference alongside the calculator above.
| ATA Length | 26" Draw | 28" Draw | 29" Draw | 30" Draw |
|---|---|---|---|---|
| 30" | 5.5" | 6.0" | 6.5" | 7.0" |
| 32" | 5.0" | 5.5" | 6.0" | 6.5" |
| 34" | 4.75" | 5.25" | 5.75" | 6.25" |
| 36" | 4.5" | 5.0" | 5.5" | 6.0" |
| 38" | 4.25" | 4.75" | 5.25" | 5.75" |
| 40"+ | 4.0" | 4.5" | 5.0" | 5.5" |
Corner-of-mouth anchors: subtract approximately 0.5" from each value above. Index release vs. thumb/hinge release: thumb/hinge anchors tend to sit slightly higher, add 0.25". All values are starting points — final position must be verified at the range.
Peep sight shopping guide
For hunting: A hooded aluminum peep in 3/16" from Amazon is the most reliable choice — low-light friendly, durable, and widely served by pro shops.
For target / 3D: A 1/8" clarifier-compatible peep from Optics Planet target accessories section works well with scope-style sights.
For string installation tools: A quality bow press and serving thread make DIY peep installation straightforward and repeatable.
Budget option: Amazon carries a wide range of peep sights across all sizes — useful if you're experimenting with sizes before committing to a serving.
Peep sight calculator FAQs
How far above the nocking point should my peep sight be?
For most compound bow setups, peep height starts between 4.5 and 7 inches above the nocking point. The exact distance depends on your draw length, axle-to-axle length, anchor point, and release type. Use the calculator above for a personalized estimate. Shorter bows need a higher peep because the steeper string angle moves the string's contact point with your eye further up from the nock.
What is the easiest way to set peep sight height?
The eyes-closed method: Nock an arrow, draw your bow with eyes closed, settle into your natural anchor point, then open your eyes. Have a helper mark the string where your dominant eye aligns with your sight housing. That mark is your peep location. Use the calculator above to get a starting point before applying this method — it makes the verification faster and more reliable.
Does axle-to-axle length affect peep sight height?
Yes, significantly. A shorter axle-to-axle creates a steeper string angle at full draw, which means the string-to-eye contact point shifts. For every 2 inches shorter in ATA, you typically need the peep about 0.25–0.5 inches higher on the string. A 30" ATA bow at 28" draw will need the peep about 0.75–1" higher than a 36" ATA bow at the same draw length and anchor.
What peep sight size should I use for hunting?
For hunting, a 3/16" (large) peep is the most popular choice. It lets in significantly more light than a 1/8" peep and is easier to align quickly on a moving animal. A 1/4" is even brighter and works well for very low-light situations. Target archers typically prefer 1/8" or 3/32" for a more precise aiming circle.
Why does my peep sight rotate out of alignment?
Peep rotation happens when the bow string has residual twist that causes the peep to spin as you draw. The fix: add or remove string twists to counter the rotation direction. Add 1–2 twists at a time, draw, and check. For persistent rotation, a tube-style peep or angled-aperture peep provides mechanical self-alignment. See the full rotation fix guide above.
Should I align my peep to my eye or to my sight?
Align to your sight. Set your sight at your primary shooting distance (20 or 30 yards), draw to anchor, and position the peep so the sight housing appears centered in the peep aperture. Aligning to your sight housing is more repeatable and accounts for the precise geometry of your shooting system — not just your eye position on a given day.
Can I set my peep sight without a bow press?
For initial positioning and verification, yes — you can temporarily hold a peep in the string without serving to test placement. For the final install, a bow press is required to properly serve the peep into the string. If you don't own a bow press, most pro shops will install and serve a peep for $15–25 and usually offer same-day service. See bow press options if you want to do future installs yourself.
How does draw length affect peep height?
Longer draw lengths generally require a slightly higher peep position because the string is pulled further back, shifting the contact geometry. A 30" draw length will typically need the peep 0.5–1" higher than a 26" draw on the same bow. This is why draw length is the primary input in the calculator — get your draw length measured accurately before setting your peep.
What happens if my peep is too high or too low?
Too high: At full draw, you look through the lower portion of the peep aperture. Your sight housing appears at the bottom of the circle. You'll unconsciously raise your head to center it, causing form problems and inconsistent anchor. Too low: The opposite — you look through the top of the peep and unconsciously drop your head. Both cause groups to open up and create long-term form habits that are hard to break.