Knowledge Base

Rule of 72

Years to Double = 72 / Annual Interest Rate

A simple mental shortcut to estimate doubling time of an investment.

At 12% p.a., your money doubles in ~6 years (72/12).

At 6% p.a. (typical FD/PF), money doubles in ~12 years.

Can also be used to calculate the rate needed to double in X years.

Most accurate for rates between 5% and 20%.

Pro Tip

Use Rule of 72 to account for inflation. If inflation is 6%, your purchasing power halves in 12 years. You MUST beat 6% to grow.

Rule of 72 - Complete Guide

Everything you need to know about Rule of 72 and how to optimize your financial strategy.

Understanding the Formula

The core calculation is based on:

Years to Double = 72 / Annual Interest Rate

Key Concepts & Rules

A simple mental shortcut to estimate doubling time of an investment.

At 12% p.a., your money doubles in ~6 years (72/12).

At 6% p.a. (typical FD/PF), money doubles in ~12 years.

Can also be used to calculate the rate needed to double in X years.

Most accurate for rates between 5% and 20%.

Expert Strategy

Use Rule of 72 to account for inflation. If inflation is 6%, your purchasing power halves in 12 years. You MUST beat 6% to grow.

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