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Projector replacement calculator
Divide the lens-to-screen distance by the picture width to get the throw ratio your mount needs; a new projector fits without moving the mount if its zoom range covers that figure. A projector 3.2 m from a 2.15 m wide picture needs 1.49:1.
Enter the two measurements from your existing installation and see which of our 293 in-stock projectors cover the ratio as-is, which fit with a slightly different picture, and which fit if the mount moves, with the smallest move for each. Every card flags lens shift and how the picture sits on your board.
1. Your existing installation
Measure from the front of the lens to the screen surface, and the width of the picture itself, not the board.
2. How much can change?
Leave both at their defaults to see what fits the mount exactly as it is.
3.20 m to the screen ÷ 2.15 m of picture. A projector fits if its zoom range covers this figure. 122 in-stock projectors fit as-is, 21 with a slightly different picture.
Fit as-is 122 in stock
Mount stays where it is and the picture is the same size.
Showing 8 of 122, best fit and lowest price first. Browse all projectors
Fit with a slightly different picture 21 in stock
Mount stays where it is; the picture width changes within your tolerance.
Showing 8 of 21, best fit and lowest price first. Browse all projectors
Throw ratio your mount needs
Lens-to-screen distance divided by picture width, for the distances and widths classrooms and meeting rooms usually measure. Find your picture width on the left and your distance along the top.
| Picture width | 2 m | 2.5 m | 3 m | 4 m | 5 m | 6 m |
|---|---|---|---|---|---|---|
| 1.5 m | 1.33:1 | 1.67:1 | 2.00:1 | 2.67:1 | 3.33:1 | 4.00:1 |
| 2.0 m | 1.00:1 | 1.25:1 | 1.50:1 | 2.00:1 | 2.50:1 | 3.00:1 |
| 2.5 m | 0.80:1 | 1.00:1 | 1.20:1 | 1.60:1 | 2.00:1 | 2.40:1 |
| 3.0 m | 0.67:1 | 0.83:1 | 1.00:1 | 1.33:1 | 1.67:1 | 2.00:1 |
Projector replacement questions, answered
Can I replace a projector without moving the mount?
Yes, if the new projector's throw ratio range covers the ratio your mount needs, which is lens-to-screen distance divided by picture width. A projector 3.2 m from a 2.15 m wide picture needs 1.49:1, so any model with a 1.35 to 2.2:1 zoom lens fits as-is. A fixed 1.2:1 lens would need to sit at 2.58 m, 62 cm closer, and a fixed 2.0:1 lens at 4.3 m, 1.1 m further back. Zoom lenses are what make like-for-like swaps work; most fixed-lens short throw models need the bracket moved.
How do I find the throw ratio my mount needs?
Measure from the front of the projector lens to the screen surface, then measure the width of the picture on the screen (not the board), and divide the first by the second. Lens to screen 3.2 m and picture width 2.15 m gives 3.2 ÷ 2.15 = 1.49:1. Compare that figure with the throw ratio on a projector's spec sheet: a single figure is a fixed lens that must match closely, and a range such as 1.35 to 2.2:1 is a zoom lens that fits anywhere inside it.
Will a 16:10 projector fit my 4:3 interactive whiteboard?
It will fit the width but not the height. A 16:10 picture is 62.5% as tall as it is wide, while a 4:3 board is 75% as tall, so on a 1.6 m wide board the picture is 1.0 m tall against 1.2 m of board, leaving about 20 cm unused, 10 cm above and below. Filling the height instead would need a 1.92 m wide picture that overhangs the board. For an interactive board the touch area is calibrated to the picture, so the unused strip simply stops being active; if that matters, replace the board with a 16:10 one at the same time.
Can I replace a lamp projector with a laser one on the same mount?
Yes. The light source makes no difference to fit; what matters is that the laser model's throw ratio covers the ratio your mount needs, and most laser business projectors carry a zoom lens with a wider range than the lamp model they replace. Check three other things before ordering: the mounting plate pattern and weight rating of the existing bracket, the picture offset (how far above or below the lens the picture sits), and whether the new model has lens shift to correct any offset difference without keystone.
What is lens shift and do I need it to replace a projector?
Lens shift moves the picture up, down or sideways optically, without moving the projector and without the distortion and resolution loss of keystone correction. You need it when the new projector's picture offset differs from the old one, which is common between brands, because the mount is fixed at a height chosen for the old model. A vertical shift of ±50% means the picture can be moved by half its own height in either direction. Where a projector lists keystone only, it will correct the trapezoid but at a small cost in sharpness.
Starting from scratch instead? The projector throw distance calculator works from a screen size, and the projector screen size calculator from the room. Read how far a projector should be from the screen or whether to choose laser or lamp, or browse all projectors.
Replacing a whole estate? Our technical team will match every room from a spreadsheet of distances and widths, and can supply and fit: talk to us.