Drawing Calculators & Tools
Free, practical calculators for drawing fundamentals — pencil grades, paper weight, perspective, proportion, value, and paper sizing.
Graphite Grade (H/B) Guide
Look up any grade from 9H to 9B on a hardness-to-darkness scale, or enter a target darkness and get the grade recommendation for it.
Paper Weight & GSM Calculator
Convert paper weight between pounds and gsm across bond, text, cover, and index stocks, plus a recommended gsm range for your medium.
Perspective Grid Generator
Place the horizon and vanishing point(s) for 1-point or 2-point perspective, and get the exact guide angle to any reference point.
Proportion & Grid-Transfer Calculator
Scale a gridded reference photo onto a larger drawing surface — get the scale factor, target cell size, and a distortion check.
Value Scale Generator
Generate an evenly stepped grayscale value scale from paper white to full black, with the exact hex code for each step.
Pencil-to-Page Size Guide
Scale a drawing between ISO 216 paper sizes (A0–A6) and get the linear/area scale factor plus a lead-width recommendation.