ThrowFit
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Screen + room → projector spec

Throw ratio calculator

Combine the desired screen diagonal and measured lens distance to calculate the throw ratio your projector must include.

Local geometry

Projector fit

No model lookup
Projected image aspect ratio
Known screen
Known room depth

Measure from the lens reference point to the image surface. Body depth, cables, zoom limits, lens shift, offset, focus, brightness, keystone, mounts, and tolerances are outside this geometry.

Calculated geometry

Required projector specification

Required throw ratio≈ 1.3175
Throw ratio≈ 1.3175
Lens distance≈ 3.5 m11.48 ft
Image diagonal120 in304.8 cm
Image width≈ 104.59 in265.66 cm
Image height≈ 58.83 in149.43 cm

r = D ÷ W = 3.5 ÷ 2.66

The aspect-ratio diagonal usually introduces a square root. ThrowFit keeps exact decimal inputs and unit conversions, then marks rounded display values with ≈.

Verify the final range, reference point, focus limits, and mounting clearance in the current manual for the exact projector and lens.