AI Tool Stack ROI Calculator

Net monthly $ saved across AI tool subscriptions, tax-adjusted.

VAT / Sales Tax Calculator

Tax-included total or reverse pre-tax price with 20+ country presets.

Average / Mean Calculator

Mean, median, mode, range, min/max and population SD for up to 10,000 values.

Area Calculator

Area (and perimeter/circumference) for eight common shapes with step-by-step working.

Volume Calculator

Volume (and surface area) for eight common 3D shapes with step-by-step working.

Aspect Ratio Calculator

Solve missing dimension, scale to a target ratio, snap to 16:9 and other standards.

Word Counter

Words, characters, sentences, paragraphs, avg word length and reading/speaking time.

Final Exam Grade Calculator

Live: what score you need on the final for a target letter grade.

Unit Converter

Length, weight, volume, temperature, area and time in one converter.

Shoe Size Converter

US Men/Women, UK, EU, JP/Mondopoint and CM with brand-fit notes.

Scientific Notation Calculator

Standard, scientific and engineering notation with order of magnitude.

Roman Numeral Converter

Roman ↔ integer 1–3999 with subtractive notation and glyph breakdown.