Pen & Pencil Tools & Calculators

Ink Refill Life Estimator

Estimate how many pages a cartridge, converter, or gel refill will write from its ink capacity and your nib or tip size — and how long that lasts at your daily writing pace.

Pencil Lead Hardness Selector

Pick the right graphite grade on the HB scale, convert between the H–B and US #2 numbering systems, and see how dark and how durable each grade writes.

Nib Size Converter

Translate a fountain-pen nib size to an approximate line width in millimetres, and convert between Western and finer Japanese sizing so a Medium means what you expect.

Pen Weight & Balance Comparator

Compare two pens by weight and by where they balance — posted or unposted — from their barrel, cap, and section masses, to find which one your hand will thank you for.

Ink Dry-Time Estimator

Estimate how long ink takes to dry from your nib width, paper absorbency, and the humidity — handy for left-handers and anyone tired of smudged lines.

EDC Carry-Weight Calculator

Add up the weight of your everyday-carry writing kit — pens, pencil, refills, notebook, and case — in grams and ounces, with a per-item breakdown and a pocket-vs-bag verdict.

Nib Size & Dry Time Reference

Every round nib size in Western and Japanese sizing, its line width, its cross-standard equivalent, and how long it takes to dry on four common paper types — all in one table.