Exposure Triangle Calculator — Aperture, Shutter Speed & ISO Equivalent Exposures

Getting the right exposure is the most fundamental skill in photography. Three settings control how much light reaches your sensor: aperture, shutter speed, and ISO. Change one, and you must adjust at least one other to maintain the same brightness. Our free Exposure Triangle Calculator lets you pick any combination and instantly see the EV value plus up to 12 equivalent exposure settings that produce the same brightness. No more mental math in the field.

What Is the Exposure Triangle?

The exposure triangle describes the relationship between three camera settings that control image brightness:

Setting	What It Controls	Side Effect
Aperture (f-stop)	Size of the lens opening	Depth of field (blur)
Shutter Speed	How long the sensor is exposed	Motion blur or freeze
ISO	Sensor sensitivity to light	Noise / grain

All three are measured in "stops" — each stop doubles or halves the amount of light. Increasing exposure by one stop in one setting requires decreasing by one stop in another to maintain the same brightness.

Exposure Value (EV) is a single number that represents the combination of all three settings. A higher EV means less light reaches the sensor (bright scene), and a lower EV means more light (dark scene). EV 0 corresponds to a 1-second exposure at f/1.0 and ISO 100.

The formula: EV = log2(N² / t) - log2(S / 100)

Where N = f-number, t = exposure time in seconds, S = ISO.

How to Use the Exposure Triangle Calculator

1. Set your aperture — click any f-stop button to select your desired depth of field.
2. Set your shutter speed — select how you want motion captured (frozen or blurred).
3. Set your ISO — choose your sensor sensitivity based on lighting conditions.
4. Read the EV — displayed prominently at the top of the tool.
5. Browse equivalent exposures — the tool shows up to 12 combinations that produce the exact same brightness, so you can trade depth of field for motion blur, or noise for sharpness.

Click any equivalent exposure to copy it to your clipboard.

Common EV Reference

Scene	Typical EV (ISO 100)
Bright snow / sand	+16
Sunny day (distinct shadows)	+15
Hazy sunlight	+14
Cloudy bright	+13
Overcast	+12
Sunset	+10 to +12
Indoor (well-lit)	+7 to +9
Indoor (dim)	+5 to +6
Candlelight	+3 to +4
Aurora / Milky Way	-3 to -5

Key Features

Feature	Description
Full Stop Scale	Standard f-stop, shutter speed, and ISO values
Live EV Calculation	Exposure Value updates instantly as you change settings
Equivalent Exposures	Up to 12 matching combinations for the same brightness
Click to Copy	Copy any equivalent exposure or your current settings
Single Card Layout	All controls and results in one clean view
Presets via Stops	Click any value to instantly see the effect

Common Use Cases

Trading Depth of Field for Sharpness

You are shooting a portrait at f/2.8, 1/250s, ISO 400. You want more depth of field (sharper background) without changing brightness. The calculator shows you can shoot at f/5.6, 1/60s, ISO 400 — same exposure, more depth of field.

Freezing Motion in Low Light

At a basketball game, you are at f/2.8, 1/250s, ISO 3200 and getting motion blur. The calculator shows you can go to f/2.8, 1/1000s, ISO 12800 — freezing the action at the cost of more noise.

Matching Settings Between Cameras

Two photographers with different lenses need matching exposures. One is at f/4, the other at f/2.8. The calculator instantly shows the corresponding shutter speed and ISO adjustments.

Learning Photography

Students can experiment with the triangle virtually — seeing how each stop change affects the others — before picking up a camera.

Night Photography Planning

Planning a Milky Way shoot? Set your widest aperture (f/2.8), your maximum usable shutter speed (15s), and your preferred ISO (3200). See the EV and find equivalent settings for different setups.

Tips and Best Practices

• Start with your creative constraint. If depth of field matters most, set aperture first. If motion matters, set shutter speed first. If noise matters, set ISO first.
• Use the lowest ISO possible. Higher ISO introduces noise. Always check if you can open the aperture or slow the shutter before raising ISO.
• Watch the shutter speed for handheld shooting. Below 1/(focal length) seconds, camera shake becomes visible. For a 50mm lens, keep shutter speed above 1/50s.
• Understand the exposure compensation relationship. If your camera's meter says +1 EV, you need to decrease exposure by one stop from the metered setting.
• Equivalent exposures are not identical images. They have the same brightness but different depth of field, motion characteristics, and noise levels.

Frequently Asked Questions

Is this Exposure Triangle Calculator free?

Yes. The tool is completely free with no usage limits, no registration, and no hidden costs.

What is EV (Exposure Value)?

EV is a number that represents the combination of aperture, shutter speed, and ISO. Higher EV means a darker exposure (less light). The calculator uses the standard EV formula referenced to ISO 100.

Why are there no third-stop or half-stop values?

This calculator uses full stops for clarity and simplicity. Most cameras offer third-stop increments, but full stops make the relationships between settings easier to understand.

How accurate are the equivalent exposures?

The equivalents use standard full-stop values and match within a fraction of a stop. In practice, the differences are imperceptible in the final image.

Can I use this for video?

Yes. The same exposure principles apply to video. Set your shutter speed based on your frame rate (typically 1/(2 × frame rate) for the 180-degree rule), then adjust aperture and ISO to match.

What is the 180-degree shutter rule for video?

For cinematic motion blur, your shutter speed should be approximately 1/(2 × frame rate). At 24fps, use 1/48s (closest standard: 1/50s). At 30fps, use 1/60s. Set this first, then adjust aperture and ISO.