Printable Snellen Eye Chart Generator — Exact Size PDF

Test distance

Paper size

Include on the chart

Metric acuity (6/6) beside each rowlogMAR and decimal acuityHow-to-use instructionsCalibration bar to verify print scale

Rows to print

Letter heights are what actually gets printed at 20 ft. Rows too wide for the paper cannot be printed at this distance.

Print	Snellen	Metric	logMAR	Letter height	Letters
Print the 20/200 row	20/200	6/60	+1.00	88.7 mm	N
Print the 20/100 row	20/100	6/30	+0.70	44.3 mm	RD
Print the 20/70 row	20/70	6/21	+0.54	31.0 mm	HZO
Print the 20/50 row	20/50	6/15	+0.40	22.2 mm	SNCV
Print the 20/40 row	20/40	6/12	+0.30	17.7 mm	KDRHO
Print the 20/30 row	20/30	6/9	+0.18	13.3 mm	ZOVSCN
Print the 20/25 row	20/25	6/7.5	+0.10	11.1 mm	DHKNVRS
Print the 20/20 row	20/20	6/6	0.00	8.9 mm	OZCHVSDK
Print the 20/15 row	20/15	6/4.5	-0.12	6.6 mm	RNHSDCOV
Print the 20/13 row	20/13	6/3.8	-0.19	5.8 mm	VKSDNOZR
Print the 20/10 row	20/10	6/3	-0.30	4.4 mm	CNHZKVSO

8 rows · 2 pages

Printing it accurately

Print at 100%. In the print dialog choose “Actual size” or set scaling to 100% — never “Fit to page”, which silently shrinks the chart and invalidates every measurement.
Check the bar. Measure the calibration bar at the foot of each sheet. If it is not exactly 100 mm, the print scaled and the chart is wrong.
Tape multi-page charts in order. Large rows land on the first sheet; join the sheets edge to edge, in order, top to bottom.
Measure the distance. Pace is not good enough — a 20 ft chart read from 18 ft flatters your acuity by roughly a line.

How the sizes are worked out

A 20/20 optotype subtends five arcminutes of visual angle, with each stroke one arcminute, so its height is 2 × distance × tan(2.5′) — 8.87 mm at 20 feet, 8.73 mm at 6 metres. Every other row is that height times its Snellen ratio, so the 20/200 row is ten times taller. The letters are Sloan optotypes (C D H K N O R S V Z), drawn here as vector outlines on the standard 5 × 5 grid with strokes exactly one fifth of the letter height; ordinary text fonts get that ratio wrong, which changes the acuity you are actually measuring. Letters are spaced one letter-width apart, as on a wall chart.

There is deliberately no red/green duochrome panel. Duochrome is a refraction test — it only means something with trial lenses in front of the eye — and consumer printer inks do not reproduce the wavelengths it depends on.

This is a screening aid for checking whether something has changed. It is not an eye examination, and it cannot detect the conditions an optometrist is looking for.