MAR values to Snellen 20/x denominators Converter
Convert MAR values to Snellen 20/x denominators using 20/x denominator = MAR × 20. The formula is 20/x denominator = MAR × 20; 1 MAR is 20 20/x.
Minimum angle of resolution, the reciprocal of decimal visual acuity.
The denominator from a 20-foot Snellen visual acuity fraction, such as 40 in 20/40.
Start with your value in MAR values, then apply the formula below. It stays visible so you can catch rounding mistakes instead of just copying the output.
Use these values for notation comparison and documentation checks only. They do not diagnose vision problems or replace an eye exam.
Visual acuity notation is often rounded to chart lines, so the converted numeric value may be more precise than the original measurement. This page displays converted values with up to 3 decimal places by default.
| MAR values | Snellen 20/x denominators |
|---|---|
| 0.5 MAR | 10 20/x |
| 0.8 MAR | 16 20/x |
| 1 MAR | 20 20/x |
| 2 MAR | 40 20/x |
| 4 MAR | 80 20/x |
| 10 MAR | 200 20/x |
Useful for comparing eye chart notation systems. Use the same formula with your exact input if the measurement needs to be documented.
Useful for translating research tables and clinical references. Use the same formula with your exact input if the measurement needs to be documented.
Useful for checking educational vision examples. Use the same formula with your exact input if the measurement needs to be documented.
How do I convert MAR values to Snellen 20/x denominators?
Enter the value in MAR values and apply 20/x denominator = MAR × 20. Round the Snellen 20/x denominators result after the conversion, not before.
What is 1 MAR value in Snellen 20/x denominators?
1 MAR equals 20 20/x with the current rounding setting. Keep more decimal places when the result feeds another calculation.
What is 0.5 MAR in 20/x?
0.5 MAR is 10 20/x. It appears in the lookup table so you can compare it with nearby amounts.
Can I convert Snellen 20/x denominators back to MAR values?
Yes. Use the reverse Snellen 20/x denominators to MAR values converter if you need to go the other direction.
How accurate is this MAR values to Snellen 20/x denominators conversion?
The calculator runs the formula in your browser and rounds results to 3 decimal places by default. Visual acuity notation is often rounded to chart lines, so the converted numeric value may be more precise than the original measurement.