Pencil Hardness Converter
Convert between the HB graphite grading scale and the US number scale for pencils.
See hardness, darkness, and common uses for each grade.
Select a pencil grade to see its properties and equivalent in other systems.
Pencils are graded on two scales: the European HB system and the US number system. The HB system is used worldwide, while the US number system is common in American schools and offices.
The HB graphite scale: The scale runs from hard (H) to black/soft (B), with F (fine point) and HB in the middle.
- H grades (2H, 3H, 4H, etc.): Harder lead, lighter marks, holds a sharp point longer.
- B grades (2B, 3B, 4B, etc.): Softer lead, darker marks, wears down faster.
- Higher numbers mean more extreme hardness or softness.
Complete comparison table:
| HB Grade | US Number | Hardness | Darkness | Common Use |
|---|---|---|---|---|
| 9H | — | Extremely hard | Very light | Technical drafting, lithography |
| 8H | — | Extremely hard | Very light | Technical drafting |
| 7H | — | Very hard | Very light | Detailed technical drawing |
| 6H | — | Very hard | Light | Technical drawing, cartography |
| 5H | — | Hard | Light | Technical drawing |
| 4H | — | Hard | Light | Technical/architectural drawing |
| 3H | — | Medium hard | Light-medium | Drafting, light sketching |
| 2H | — | Medium hard | Medium-light | Drafting, detailed outlines |
| H | — | Slightly hard | Medium | Technical sketching, fine details |
| F | — | Firm | Medium | Writing, fine-point drafting |
| HB | #2 | Medium | Medium | General writing (standard pencil) |
| B | #1 | Slightly soft | Medium-dark | Writing, sketching |
| 2B | — | Soft | Dark | Drawing, sketching, shading |
| 3B | — | Soft | Dark | Freehand drawing, shading |
| 4B | — | Very soft | Very dark | Expressive drawing, bold shading |
| 5B | — | Very soft | Very dark | Rich shading, charcoal-like effects |
| 6B | — | Extremely soft | Extremely dark | Heavy shading, dramatic contrast |
| 7B | — | Extremely soft | Extremely dark | Thick bold lines, expressive art |
| 8B | — | Extremely soft | Near-black | Maximum darkness, broad strokes |
| 9B | — | Extremely soft | Near-black | Deepest blacks possible |
US number to HB equivalents:
| US Number | HB Equivalent |
|---|---|
| #1 | B |
| #2 | HB |
| #2.5 | F |
| #3 | H |
| #4 | 2H |
What determines pencil hardness? The graphite-to-clay ratio in the pencil core determines its hardness. More clay makes the lead harder and lighter (H grades). More graphite makes the lead softer and darker (B grades). HB has a balanced mix of graphite and clay.
Practical guide for choosing pencils:
- Standard writing: HB or #2 is the universal choice. This is required for scantron/standardized test forms.
- Sketching and drawing: Keep a range from 2H (light outlines) to 6B (deep shadows).
- Technical drafting: Use H to 4H grades for precise, light lines that do not smudge.