Rule of 3 - Direct & Inverse

Type three values and the empty box solves itself. Direct and inverse rule of three. Free, no ads, works offline.

Rule of 3 - Direct & Inverse: solve any proportion in seconds.

Type three values and the empty box is calculated automatically. No formulas to remember.

HOW IT WORKS

• Direct rule of three: the more, the more. If 3 items cost $45, how much do 7 cost?
• Inverse rule of three: the more, the less. If 4 workers take 6 hours, how long do 8 take?
• The result updates instantly as you type
• Your numbers are saved automatically: take a call, come back, everything is still there

SIMPLE ON PURPOSE

• Works completely offline
• No accounts, no ads, no data collection
• Free

Perfect for shopping, cooking, work and school: scaling recipes, converting units, calculating prices, percentages and much more.