A test-grade calculator converts the number of correct answers out of a total to a percentage and a letter grade. The Toolenza calculator uses the standard US 10-point scale (A ≥ 90%, B ≥ 80%, C ≥ 70%, D ≥ 60%, F < 60%) by default, with a +/- modifier scheme available.

The standard US scale

• A — 93–100% (with A− at 90–92%, A+ at 97–100% on +/− scales).
• B — 83–92% (B− 80–82%, B+ 87–92%).
• C — 73–82% (C− 70–72%, C+ 77–82%).
• D — 63–72% (D− 60–62%, D+ 67–72%).
• F — below 60% (or 63%, depending on the institution).

The +/- scheme isn't universal — many universities use plain A/B/C/D/F, and some use a 4.0-equivalent that maps 93–100 → 4.0, 90–92 → 3.7, etc. Always check your specific school's policy.

International variants

• UK first/2:1/2:2/third class — typically 70%/60%/50%/40% boundaries.
• Germany — 1 (best) to 5 (fail), with 1.0 = 92%+, 4.0 = 50% (pass), 5.0 = below 50%.
• France — out of 20; 16+ = A-equivalent, 14+ = B, 12+ = C, 10+ = pass.
• India — typically 35% pass mark, with first-class at 60% and distinction at 75%.

How a single bad answer hurts

On a 20-question test, each wrong answer is 5 percentage points — enough to drop one letter grade. On a 100-question test, each wrong answer is 1 point. Higher question counts mean smaller per-question stakes — which is why standardised tests have many short questions instead of few weighted ones.

Pitfall

Curving — when an instructor scales raw scores, the percentage no longer maps directly to the letter grade. Most curving methods either add a constant or fit a target distribution; both make raw-percent → letter conversion meaningless without the curve.