A red dot mount's height is the distance from the rail to the centre of the optic — and it decides how your sight lines up with your iron sights and how heads-up your shooting position feels. Here's a quick reference to the four heights you'll see most on AR-pattern rifles. Want the full explainer? Read co-witness heights explained.
Mount height chart
Heights are approximate optical centreline above the rail and vary slightly by brand — always check the maker's spec.
| Height | ≈ Centreline | What it does | Best for |
| Low / pistol | ~0.5–1.0 in | Sits the optic close to the bore | Pistols, bolt-actions, low mounts |
| Absolute co-witness | ~1.41 in | Irons appear centred in the dot window | Backup irons in the middle of the glass |
| Lower 1/3 co-witness | ~1.54 in | Irons sit in the lower third of the window | The most popular AR red dot height |
| 1.93 in | 1.93 in | Taller, heads-up position | Modern “heads-up” builds, faster target transitions |
| 2.26 in | 2.26 in | Tallest common height | PCCs, night vision and very heads-up setups |
Co-witness: absolute vs lower 1/3
Co-witness means your iron sights line up through the optic as a backup. Absolute puts the irons dead-centre in the dot window; lower 1/3 tucks them into the bottom third, leaving a cleaner view for the dot while irons stay available. Lower 1/3 is the most common choice for AR red dots.
Why go taller (1.93in / 2.26in)?
Taller mounts raise the optic to a more natural, “heads-up” head position — less neck strain, faster acquisition, and clearance for night-vision or magnifier setups. They've become hugely popular on modern carbines, though you lose iron co-witness at these heights.
Find the right mount
Browse red dot sight mounts and rifle scope mounts by height, or build a complete setup via AR-15 optics. Many quick-detach mounts (like the American Defense range) are offered in several heights including a 2.33in night-vision option.
Frequently asked questions
Which height is best for an AR-15 red dot?
Lower 1/3 co-witness is the most popular all-round choice; 1.93in is the go-to if you prefer a taller heads-up position.
What does “1.93” mean?
It's the optic's centreline height above the rail in inches — taller than co-witness heights for a heads-up shooting posture.
Do I lose iron co-witness with a tall mount?
Yes — at 1.93in and 2.26in your irons no longer line up through the optic, so plan for offset or folding sights if you want backups.
UK Delivery & Support
All mounts are UK-stocked and dispatched tracked from our UK warehouse — no import duties or customs delays — with UK-based support to help you pick the right height.