f/8 · 1/250 · ISO 100
Depth of Field, Computed From Your Exact Camera
Every calculator here runs entirely in your browser, uses your real sensor format, and gives a linkable result — not a generic table that ignores what you actually shoot with.
Why a Calculator Beats a Chart
Search "depth of field calculator" and most of what comes back is either a static chart glued to one sensor size, a forum thread arguing about circle-of-confusion conventions, or a page so cluttered with ads that the number you actually need is three scrolls down. None of them know what you're shooting with. A hyperfocal distance at f/8 on a full-frame 24mm is a completely different number than the same f/8 and the same 24mm on a Micro Four Thirds body — roughly double the distance, not half, because Micro Four Thirds' smaller sensor demands a stricter circle of confusion, the acceptable-blur threshold the whole calculation is built on.
FocalMath exists because that dependency — sensor format, focal length, aperture, subject distance — is exactly what a snippet or a static chart can't capture, and exactly what a real calculator can. Every number on this site is computed at the moment you ask for it, from formulas you can read in the reference pages, using your actual sensor's real physical dimensions rather than a rounded-off assumption.
What's Actually Here
Five calculators, each solving one real problem a working photographer runs into in the field: depth of field and hyperfocal distance, the exposure triangle (lock two variables, solve the third), astro shutter-speed limits before stars start to trail, crop-factor equivalence between camera systems, and print size at a given viewing distance. Every one of them runs entirely in your browser — nothing you type is uploaded anywhere — and every meaningful result gets its own shareable link, so "hyperfocal distance at 24mm f/8 on full frame" is a real page you can bookmark or send to someone, not a state that vanishes when you close the tab.
Underneath the tools sits a reference layer built the same way: real sensor dimensions for 17 formats from full frame down to 1/2.3", real specs for genuinely popular camera bodies across every major system, and a curated set of answers to the specific questions photographers actually type into a search bar — not a generated grid of every focal length crossed with every aperture crossed with every sensor, which would just be noise wearing a search-engine costume.
The Numbers That Trip People Up
Two things on this site exist specifically because they're commonly gotten wrong. First: sensor size changes depth of field at a given f-number, but it does NOT change exposure — f/2.8 lets in the same light and needs the same shutter speed at the same ISO no matter what's behind the lens. The crop-factor tool keeps those two effects visibly separate instead of blurring them into one "equivalent aperture" number, which is where most confusion starts. Second: the classic "500 rule" for astro shutter speed is a rough rule of thumb from the film era, not a physical law — the more accurate NPF rule accounts for your camera's actual pixel pitch and the star's declination, and the astro calculator shows both side by side so you can see how far apart they land.
Every Calculator
Most Searched
Frequently Asked Questions
Do I need to create an account to use the calculators?
No. Every calculator runs client-side in your browser with no login, no upload and no tracking of what you type into it.
Which sensor formats are supported?
17 real formats, from full frame and APS-C (Canon's 1.6x and the 1.5x used by Nikon/Sony/Fujifilm) through Micro Four Thirds, 1-inch and smaller compact sensors, medium format, and several large-format and film formats — see the full sensor reference for the complete list with real dimensions.
Where does the circle of confusion value come from?
Each sensor page states it explicitly: this site uses the diagonal/1500 convention, a widely published rule of thumb. Other sources use diagonal/1442 or a stricter diagonal/1730, which will give slightly different hyperfocal numbers — the difference is usually small enough not to matter for field use, but it's stated rather than hidden.
Is the 500 rule for astrophotography accurate?
It's a rough, camera-agnostic rule of thumb from the film era — useful for a fast mental estimate, but it ignores your camera's actual pixel pitch and the target star's declination, both of which genuinely change how long you can expose before trailing becomes visible. The NPF rule accounts for both; the Astro 500/NPF Calculator shows both numbers together.