UsefulFormula1400+ Useful Formulas for Everyday Life

Docs About FAQ Contact

Human Relationships & Social Life

Friendship Reciprocity %

Help Given ÷ Help Received × 100

© 2025 UsefulFormula

1400+ formulas across math, physics, chemistry, engineering, finance, health, and everyday life — free and easy to use.

↑ Back to top

Categories

Math Formulas Physics Formulas Chemistry Formulas Engineering Formulas Finance Formulas Health Formulas Everyday Life Formulas

Resources

Docs All Formulas

Help

FAQ — Useful formulas & calculators About Us Contact Terms Privacy