Focal Length to Lens Angle Calculator
Convert camera lens focal length to angle of view. See exactly how wide or narrow your lens captures the scene.
Lens Settings
The focal length printed on your lens (e.g., 24mm, 50mm, 200mm)
Popular Focal Lengths:
Angle of View Results
Set your camera sensor and focal length to see the angle of view
Why Focal Length Alone Can Be Misleading
When shopping for lenses or planning shots, people often focus only on the focal length number printed on the lens. "I need a 50mm lens," they say. But that number by itself doesn't tell the whole story. Two lenses with the same focal length can show completely different amounts of the scene depending on what camera they're used on.
The key factor most people miss is sensor size. A 50mm lens on a full-frame camera (like Canon EOS R5 or Nikon Z6) will give you a very different angle of view than the same 50mm lens on a crop sensor camera (like Canon EOS Rebel or Nikon D3500). The smaller the sensor, the more "zoomed in" the lens appears to be.
This calculator bridges that gap by showing you the actual angle of view your lens will capture. Instead of guessing whether a lens will be "wide enough" or "zoomed in enough," you can see exactly how much of the scene will fit in your photo. It's the difference between buying a lens based on hope and buying one based on facts.
Common Lens Categories Explained
Lens categories aren't just marketing—they're based on practical photography considerations. Different focal lengths serve different purposes, and understanding these categories helps you choose the right lens for your needs.
| Lens Type | Typical Focal Length | Best For | Angle of View |
|---|---|---|---|
| Ultra-Wide | 10–20mm | Architecture, landscapes, dramatic shots | 100°+ |
| Wide Angle | 24–35mm | Street photography, environmental portraits | 60–84° |
| Standard | 40–60mm | General photography, portraits, everyday shooting | 40–57° |
| Telephoto | 70mm+ | Sports, wildlife, portrait telephotos | Less than 40° |
These ranges are general guidelines and can vary slightly depending on your camera's sensor size. The angles shown are for diagonal view on full-frame cameras. Your actual angles may differ with crop sensors.
Full-Frame Camera Examples
Here's how common focal lengths translate to angles of view on a full-frame camera (36×24mm sensor):
| Focal Length | Diagonal Angle | Horizontal Angle | Lens Category | Typical Use |
|---|---|---|---|---|
| 16mm | ~108° | ~97° | Ultra-wide | Architecture, dramatic landscapes |
| 24mm | ~84° | ~74° | Wide | Street photography, environmental portraits |
| 35mm | ~63° | ~54° | Wide | Street, travel, photojournalism |
| 50mm | ~47° | ~40° | Standard | Portraits, general photography |
| 85mm | ~29° | ~24° | Telephoto | Portrait telephotos, headshots |
| 135mm | ~18° | ~15° | Telephoto | Sports, wildlife, fashion |
| 200mm | ~12° | ~10° | Telephoto | Wildlife, sports, bird photography |
Important Note: These angles are for diagonal view. Horizontal and vertical angles will be smaller. Crop sensor cameras will have narrower angles with the same focal length lenses.
Step-by-Step Example
Let's calculate the angle of view for a 35mm lens on a full-frame camera:
| Step | Process | Calculation |
|---|---|---|
| Step 1 | Choose sensor size | Full-frame: 36mm × 24mm |
| Step 2 | Enter focal length | 35mm lens |
| Step 3 | Apply angle formula | Angle = 2 × arctan(36 ÷ (2 × 35)) |
| Step 4 | Interpret the result | ~63° diagonal angle of view |
The 63° diagonal angle means this lens will capture a moderately wide view of the scene. It's wider than a standard lens but not as wide as an ultra-wide lens. This makes it great for street photography, environmental portraits, and travel photography where you want some context around your subject.
How the Calculator Uses Add Formula Logic
The Core Angle Formula
Angle of View = 2 × arctan(Sensor Dimension ÷ (2 × Focal Length))
The calculator uses trigonometry to determine how much of the scene your lens will capture. It takes into account both your camera's sensor size and the lens focal length to give you the precise angle.
The formula works by:
- Using the sensor dimension (width for horizontal angle, height for vertical, diagonal for diagonal)
- Dividing by twice the focal length to get the tangent of half the angle
- Taking the arctangent to convert back to an angle measurement
- Doubling the result to get the full angle of view
When This Calculator Is Useful
Lens Buying Decisions: Before purchasing a new lens, use this calculator to confirm it will give you the field of view you need. Don't buy a lens based on the focal length number alone—see what it actually captures.
Shot Planning: Whether you're shooting video or stills, knowing your angle of view helps you plan compositions. You can determine if a lens will fit your subject in frame or if you need to move closer or farther away.
Learning Photography: Understanding angle of view is fundamental to photography. This calculator helps students visualize how different lenses affect their images and why certain lenses are used for specific purposes.
Video Production: Consistent angles are crucial in video work. Use this calculator to match angles across different cameras or to ensure your lens choice matches your production requirements.
Camera System Comparison: If you're considering switching between camera brands or sensor sizes, this calculator helps you understand how your existing lenses will perform on the new system.
What Makes This Calculator Different
Most lens angle calculators are either overly technical (showing complex formulas) or too simplistic (ignoring sensor size). This calculator strikes the perfect balance by accounting for sensor size while keeping explanations accessible. It doesn't assume you know what crop factor means or why sensor size matters.
The sensor presets make it easy to get started without having to look up technical specifications. Just click on your camera type (Full Frame, APS-C, Micro Four Thirds) and you're ready to go. The calculator handles the crop factor calculations automatically so you don't have to do them yourself.
What really sets it apart is the educational approach. Instead of just giving you a number, it explains what that number means in practical terms. It tells you whether your lens will be wide, narrow, or somewhere in between. It helps you understand not just the "what" but the "why" and "so what" of lens angles. Most importantly, it teaches you to think about field of view rather than just focal length numbers.