Buying
How much does a thermal camera cost?
Thermal cameras run from a phone attachment to a professional instrument, and the price is driven by one number — how many pixels the sensor has.
Updated
The price of a thermal camera is set almost entirely by its sensor resolution, and the jumps are steep: roughly a doubling of pixels doubles or triples the price. Everything else — screen, battery, ruggedness, software — is a rounding error next to that.
Here is what the bands actually buy.
Phone attachments
The cheapest way in. A small module plugs into USB-C or Lightning and your phone provides the screen, the battery and the software.
Typical sensors run from 80×60 (FLIR One Gen 3) up to 256×192 (Topdon TC001, InfiRay P2 Pro). Good enough to find a draught, trace underfloor heating, or check whether a breaker is running hot. Not good enough to read a scene at distance.
Watch for two things: the module draws power from your phone, and the cheaper ones have a narrow field of view, so you end up standing further back than you would like.
Entry-level handheld
A self-contained device with its own screen, usually 160×120 or 206×156. The advantage over an attachment is that it is a tool rather than an accessory — it survives a van, it has a proper trigger, and it does not flatten your phone.
This is where most home users and one-person trades land.
Mid-range handheld
320×240, sometimes 384×288. This is the band where the image stops being a suggestion and starts being readable: you can see the shape of a stud wall rather than a vague warm blur, and measure a smaller target from further away.
For anyone billing for thermography — building surveys, electrical inspection reports — this is usually the floor.
Professional
640×480 and up, with better thermal sensitivity (measured in millikelvin), interchangeable lenses and calibrated accuracy you can put in a report. Prices here are in the same territory as a good used car, and the buyers are inspection firms, utilities and industry.
Cooled scientific
A different technology entirely: the detector is held near 77 K, which makes it sensitive enough to resolve hundredths of a degree and fast enough for research. The cooler is a moving part with a service life. If you have to ask, this is not your band.
The cheaper answer: rent one
Most people asking this question need a thermal camera for one afternoon — to find why the back bedroom is cold. Tool hire shops, and in several countries the public library, rent them by the day for a small fraction of the purchase price. For a single job that is almost always the right call.
What the specs actually mean
- Resolution — the number of real thermal pixels. Ignore any “enhanced” or interpolated figure; a 160×120 sensor upscaled to 640×480 is still 160×120.
- Thermal sensitivity (NETD) — the smallest temperature difference it can resolve, in millikelvin. Under 50 mK is good.
- Field of view — a narrow lens sees further but less. This matters more than people expect indoors.
- Accuracy — usually ±2 °C or ±2 %. Nothing in the consumer range is a calibrated laboratory instrument.
And the free option
An app costs nothing and measures nothing. It takes the brightness of your ordinary camera picture and maps it onto thermal palettes, which produces the look and no data. That is genuinely fun for photos and video, and it is useless for finding out why your bedroom is cold.
Thermal Camera is that kind of app and says so. If you need a number, use one of the bands above — we would rather point you at the right tool than sell you the wrong one.