Projector brightness and throw distance calculator

Enter the image size, the room’s lighting and the kind of lens. You’ll get the brightness you need and how far from the screen the projector goes.

How brightness and throw are worked out

The brightness a projector needs grows with the area of the image and with the light already in the room. The calculator multiplies the screen area by a factor for the lighting you choose, adjusts for the screen’s gain, and rounds up to a common projector brightness.

Throw distance is the image width multiplied by the lens’s throw ratio. Ratios vary by model, so the result shows a typical range for each lens type; check the exact figures for the projector you choose.

Questions

How many lumens do I need for a classroom?

With the lights on, a typical classroom image of about 3 m wide needs around 5,000 to 6,000 lumens. Larger screens or daylight need more.

What is a throw ratio?

The distance from the lens to the screen divided by the image width. A 1.5 ratio projects a 3 m wide image from 4.5 m away.

When is a flat panel better than a projector?

In bright rooms, and for images up to about 98″, flat panels give a sharper and brighter picture with no lamp or shadows to manage.

Design the whole room

RoomSpec turns a site survey into a certified Teams or Zoom design, bill of materials and proposal in minutes. Join the waitlist for early access.

Join the waitlist

More free tools

Display sizeThe right screen size for any meeting room, from the farthest seat.LED wallPixel pitch, resolution, weight and power for an LED or LCD video wall.Certified devicesIs that device certified for Teams Rooms or Zoom Rooms, and until when?Room sizeHow many seats a room holds, its room class, and the kit it needs.Room acousticsReverberation time from the room’s finishes, or measure it with a clap.Network and PoEBandwidth, firewall ports and PoE budget for Teams Rooms or Zoom Rooms.Speaker coverageHow many ceiling speakers and microphones a room needs, and where.