How we score thermal monoculars
One formula, the same for every monocular, published in full so you can redo any score yourself.
Last updated November 9, 2026 · prices checked November 9, 2026
The rules
- Where the figures come from. Our scores come from manufacturer data, published prices and the formula on this page.
- Each criterion is scored out of 10 on a fixed scale (below), then combined with published weights.
- A missing figure is never guessed. The criterion is left out and the other weights are rescaled. Example: Vortex and ATN do not state a NETD figure for the Veil 400 and the OTS LT 320, so sensitivity is left out of their scores.
- When a brand states two figures, we keep the less flattering one. Pulsar lists a sensor NETD and a system NETD for some models: the higher number is scored. When a weight is given without battery, we add 45 g for one 18650 cell so every model is weighed ready to use.
- No score without a price, or with fewer than 3 known technical criteria (warranty and price do not count as technical).
- Rankings by use change the weights only, never the figures. Models sold only through dealers are scored at the maker's MSRP.
- No brand pays for a place. Some links are affiliate links: we may earn a commission at no extra cost to you. It never changes our scores.
Criteria, scales and overall weights
| Criterion | Overall weight | How it is scored (value = points out of 10, straight line in between) |
|---|---|---|
| Sensor resolution | 20% | Pixels on the thermal sensor (width × height): 19,200 px = 2, 49,152 px = 5, 76,800 px = 6.2, 110,592 px = 7.3, 120,000 px = 7.6, 307,200 px = 9.3, 327,680 px = 9.4, 1,310,720 px = 10. 256×192 = 49,152; 384×288 = 110,592; 640×480 = 307,200. |
| Reach (lens / pixel pitch) | 15% | Computed reach in meters: 400 m = 3, 650 m = 5, 950 m = 6.5, 1,250 m = 7.5, 1,750 m = 9, 2,500 m = 10. Reach = focal length ÷ pixel pitch × 1.8 m ÷ 3 px, i.e. the distance at which a 1.8 m (6 ft) target covers 3 pixels. One formula for every model, because each brand defines its own "detection range" (different targets, different odds). Brand figures are shown on each review, not scored. |
| Thermal sensitivity (NETD) | 10% | NETD in millikelvin, lower is better: 15 mK = 10, 20 mK = 9, 25 mK = 8, 35 mK = 6.5, 40 mK = 6, 50 mK = 4.5. A lower NETD separates small temperature differences: a deer in warm grass, detail on a damp night. |
| Display resolution | 5% | Display megapixels: 0.3 MP = 4, 0.48 MP = 6, 0.79 MP = 8, 1.23 MP = 9, 6.5 MP = 10. |
| Battery life | 10% | Hours stated by the maker for one battery or pack: 4 h = 4, 5 h = 5, 6 h = 6, 8 h = 8, 11 h = 9.5, 16 h = 10. |
| Weight (with battery) | 10% | Weight with battery: 250 g = 10, 350 g = 9, 450 g = 8, 600 g = 6.5, 750 g = 5, 900 g = 4. |
| Laser rangefinder | 5% | Built-in laser rangefinder = 10, none = 4. |
| Water protection | 5% | IP67 or IPX7 (submersion) = 10, "waterproof" without an IP code = 7, "weather resistant" = 5. |
| Warranty | 5% | Lifetime = 10, 5 years or more = 9, 3 years = 7.5, 2 years = 6, less = 4. Factory warranty without conditions (Pulsar's extra 2 years after registration are mentioned in reviews, not scored). |
| Price | 15% | Checked price (sale price when lower, MSRP for dealer-only models) divided by the median price of all compared monoculars ($1,697): ratio 0.25× = 9, 0.5× = 8, 1× = 6, 2× = 3.5, 3× = 2. |
From criteria to the displayed score
raw score = Σ (criterion score × weight) ÷ Σ (weights of the known criteria) displayed score = 7.4 + 0.4 × (raw score − 4), kept between 7.0 and 9.8, rounded to 0.1
The displayed scale spreads the scores of current models, all serious products, on a readable range without changing their order. Labels: Excellent from 9.0, Very good from 8.5, Good from 8.0, Fair from 0.0. Ties are broken by the raw score, then by the lower price.
Weights of the rankings by use
Each ranking re-weights the same criterion scores. A weight of 0 means the criterion does not count for that use.
| Criterion | Overall | Hunting | Value | Carry | Rangefinder |
|---|---|---|---|---|---|
| Sensor resolution | 20% | 20% | 15% | 15% | 20% |
| Reach (lens / pixel pitch) | 15% | 25% | 10% | 10% | 25% |
| Thermal sensitivity (NETD) | 10% | 15% | 5% | 5% | 10% |
| Display resolution | 5% | 0% | 0% | 0% | 5% |
| Battery life | 10% | 10% | 10% | 15% | 10% |
| Weight (with battery) | 10% | 5% | 5% | 35% | 10% |
| Laser rangefinder | 5% | 10% | 0% | 0% | 0% |
| Water protection | 5% | 5% | 5% | 5% | 5% |
| Warranty | 5% | 0% | 10% | 0% | 5% |
| Price | 15% | 10% | 40% | 15% | 10% |
Eligibility per ranking: main ranking: every thermal monocular in our catalog that you can buy in the US today, from the $409.99 TOPDON TS004 to the $3,699.97 Pulsar Telos LRF XP50; best thermal monocular for hunting: every rated monocular, re-weighted for night hunting: reach, sensor resolution, sensitivity and a rangefinder count more, display and warranty less; best budget thermal monocular: thermal monoculars with a checked US price of $1,200 or less, scored with value weights (price 40%, warranty 10%); best compact thermal monocular: handheld monoculars that weigh 450 g (about 1 lb) or less with a battery, the ones that live in a jacket pocket; best thermal monocular with rangefinder: thermal monoculars with a built-in laser rangefinder (LRF), ranked on everything else that matters once the LRF is a given.
Every criterion score
Criterion scores out of 10 for each monocular ("–" = figure not published, criterion left out).
| Monocular | Sensor resolution | Reach | Thermal sensitivity | Display resolution | Battery life | Weight | Laser rangefinder | Water protection | Warranty | Price | Score |
|---|---|---|---|---|---|---|---|---|---|---|---|
| Nocpix Vista H35R | 9.4 | 9.0 | 10.0 | 10.0 | 5.5 | 6.1 | 10.0 | 10.0 | 9.0 | 3.6 | 9.0 |
| Axion 2 LRF XG35 | 9.3 | 9.0 | 6.0 | 8.0 | 7.0 | 9.0 | 10.0 | 10.0 | 7.5 | 4.1 | 8.9 |
| Telos LRF XP50 | 9.3 | 9.0 | 9.4 | 8.0 | 8.3 | 5.3 | 10.0 | 10.0 | 7.5 | 3.2 | 8.9 |
| Axion 2 XG35 | 9.3 | 9.0 | 6.0 | 8.0 | 7.0 | 8.7 | 4.0 | 10.0 | 7.5 | 4.8 | 8.8 |
| Taipan V2 19-384 | 7.3 | 6.5 | 9.0 | 8.0 | 6.5 | 9.0 | 4.0 | 10.0 | 9.0 | 7.2 | 8.8 |
| ReachIR LRF 25-384 | 7.3 | 7.5 | 9.0 | 8.0 | 4.5 | 8.2 | 10.0 | 10.0 | 9.0 | 5.7 | 8.8 |
| RIX Pocket K3 | 7.3 | 5.5 | 8.0 | 6.0 | 6.0 | 10.0 | 4.0 | 10.0 | 9.0 | 8.1 | 8.7 |
| TS004 Pro | 7.3 | 6.5 | 6.0 | 6.0 | 9.0 | 9.4 | 4.0 | 10.0 | 4.0 | 7.9 | 8.7 |
| Axion XQ19 | 7.3 | 5.1 | 8.0 | 4.0 | 8.0 | 10.0 | 4.0 | 10.0 | 7.5 | 7.5 | 8.7 |
| Vortex Veil 400 | 7.6 | 7.5 | – | 8.0 | 4.5 | 8.7 | 4.0 | 7.0 | 10.0 | 5.1 | 8.5 |
| TOPDON TS004 | 5.0 | 5.0 | 6.0 | 6.0 | 9.5 | 9.2 | 4.0 | 10.0 | 4.0 | 9.0 | 8.5 |
| Taipan V2 10-256 | 5.0 | 3.8 | 6.5 | 9.0 | 7.0 | 9.4 | 4.0 | 10.0 | 9.0 | 8.7 | 8.5 |
| ATN OTS LT 320 | 6.2 | 7.5 | – | 9.0 | 8.5 | 6.9 | 4.0 | 5.0 | 7.5 | 6.5 | 8.5 |
| Burris BTH35 v3 | 7.6 | 9.0 | 4.5 | 9.0 | 5.0 | 6.2 | 4.0 | 7.0 | 7.5 | 5.3 | 8.4 |
What the formula does not see
Image processing, menu logic in the dark, button feel with gloves, real battery life at 10 °F, rangefinder speed and customer service do not appear on spec sheets, so they are not in the score. That is why each review also says who the monocular suits and who should skip it. Color palettes, apps and recording are listed but not scored: almost every model has them.
Found an error? Write to contact@best-thermal-monocular.com with the official page that settles it.