Depth of Field Calculator
Calculate how much is in focus from sensor size, focal length and aperture
Depth of field is the part of your photo that is sharp, from front to back. The wider your aperture (lower f-number), the shallower it gets. Enter your camera, focal length, aperture and distance to see exactly how much is in focus.
Focus zone
Sweet spot of your lens
The sweet spot is the sharpest aperture of a lens. Lenses are usually slightly softer wide-open and softer again at f/16-f/22 due to diffraction. The sweet spot lies in between, typically 2-3 stops from wide-open.
Depth of Field Calculator: how it works
The depth of field calculator tells you how much of your scene will be in focus, based on sensor size, focal length and aperture. Use it when you want to know in advance whether a background will blur enough, or whether a landscape will be sharp from front to back. Enter your values and you get the result instantly.
What controls depth of field?
Three variables define it: the distance to your subject, the aperture and the focal length of your lens. A wider aperture (lower f-number) means shallower depth of field. An 85mm lens at f/1.8 and two metres gives you a completely different result than a 35mm at f/4 at the same distance.
Sensor size matters too. A full-frame sensor produces shallower depth of field at the same settings compared to a crop sensor, because you either stand closer or use a longer focal length to achieve the same framing. The calculator accounts for this.
Applying depth of field in portrait and landscape photography
In portrait work you usually want a blurred background. A wide aperture (f/1.4 to f/2.8) combined with a longer focal length gives you that narrow zone of sharpness. The calculator shows you exactly how thin that zone is, so you know how precise your focus needs to be.
In landscape and architecture photography you want the opposite: everything sharp from foreground to horizon. The calculator tells you at which aperture and focus distance that becomes achievable. If you are still deciding on a focal length for a specific scene, the Focal Length Comparison tool can help you think that through.
Frequently asked questions
What aperture do I need to blur the background when shooting a portrait at 1.5 metres?
It depends on your focal length and sensor size, but on full frame with an 85mm lens you already get a very shallow zone of sharpness at f/2.8. Enter your exact settings in the calculator to see the precise numbers for your setup.
Does a longer focal length always give shallower depth of field?
Not exactly. A longer focal length gives shallower depth of field at the same focus distance, but if you step back to keep the same framing, that partially offsets the effect. The calculator makes this clear when you compare both scenarios side by side.
How much difference in depth of field is there between full frame and APS-C with the same lens?
At the same focal length and aperture, APS-C gives you more depth of field than full frame. If you want the same framing and the same background blur on APS-C, you need to shoot at a wider aperture to match the full-frame result.