What is purchasing power?

Purchasing power is the real value of your money - what it can actually buy in goods, services, and assets. It is not the same as your rand balance. If your bank balance grows but prices and money supply grow faster, your purchasing power has dropped.

How does M3 money supply affect my purchasing power?

When M3 grows, the total number of rands in the economy increases. Each existing rand represents a smaller share of the total. This creates downward pressure on purchasing power even if consumer prices (CPI) appear stable.

Why does this site use M3 instead of CPI?

CPI tracks a basket of consumer goods, which is useful but incomplete. M3 tracks the total money supply, providing a broader view of monetary dilution. This helps answer: how much did my money need to grow just to maintain its position against the expanding rand supply?

Reading time: 4 minutes · Published: Mar 2025

TL;DR: Purchasing power is what your rands can actually buy - not the number on your bank statement. When M3 money supply grows, each rand competes with more rands for the same goods and services. Your balance can go up while your real wealth goes down.

Purchasing Power vs Money Supply

Purchasing power is not just about the number of rands you hold. It is about what those rands can command in the real economy.

Money supply is the total quantity of money available in an economy. M3 is a broad measure that includes cash, deposits, and other liquid money-like balances. When M3 rises, the number of rands competing for goods, services, labour, property, and financial assets increases.

The Core Idea

If the supply of money grows faster than the supply of real goods and services, the purchasing power of each unit of money tends to weaken. The process is not perfectly smooth. Some prices move first, some move later, and some assets may absorb the pressure before consumer prices do. But over long periods, monetary expansion matters.

Key insight: R10,000 in cash that never grows is not standing still. If M3 grows 10% in a year, that R10,000 represents a smaller slice of the economy. You need R11,000 just to maintain your relative position - before any actual price increases.

This is why cash can be risky even when the bank balance looks stable. A R10,000 balance that does not grow is not standing still if the total supply of rands is expanding around it. It is becoming a smaller claim on the economy.

Why This Site Uses M3

M3 is not a perfect measure of inflation, wealth, or living costs. It does not tell you exactly what groceries, rent, or property will cost next month. What it does provide is a broad view of monetary dilution. It helps answer a useful question: how much did my money need to grow just to maintain its position against the expanding rand supply?

That question is especially important for salaries, savings, retirement planning, and long-term asset comparisons. If your income or savings grow slower than M3, you may be losing purchasing power even before you compare yourself with property, equities, or other scarce assets.

How to Use the Data

Use the calculator to enter an amount and date range. The result estimates what that amount would need to be worth today to keep pace with M3 growth. Use the data page to inspect the monthly M3 values behind the calculation.

The goal is not to produce a perfect inflation number. The goal is to make monetary debasement visible enough that you can ask better questions about your salary, savings, prices, and long-term financial decisions.