Why finance counts in hundredths of a percent
A basis point is one hundredth of a percentage point: 100 bps = 1%. The unit exists to remove an ambiguity that costs real money. "The fee rose by 1%" can mean from 2% to 3%, or from 2% to 2.02%. "Rose by 100 basis points" can only mean the first.
The two conversions
Worked example: 50 bps on $100,000
- 50 bps = 0.50%
- 100,000 × 50 ÷ 10,000 = $500 a year
That is a typical difference between a low-cost index fund and an actively managed one. Over 25 years at 7%, paying that extra $500 a year on a growing balance costs roughly $60,000 of final value — far more than the sum of the fees themselves, because the money removed would have compounded.
Common quantities in basis points
| bps | Percent | Typically |
|---|---|---|
| 3 | 0.03% | Cheapest index fund fees |
| 25 | 0.25% | One standard central bank rate move |
| 50 | 0.50% | A larger rate move; a typical fund fee |
| 100 | 1.00% | Advisory fee; a full point of rate |
| 300 | 3.00% | Credit spread on unsecured lending |
Where the unit shows up
Rates. Central banks move in 25 bps steps. On a $300,000 mortgage over 30 years, a 25 bps cut is about $45 a month and roughly $16,000 over the term.
Spreads. A corporate bond quoted at "government plus 180 bps" pays 1.8 points above the equivalent government bond, and that gap is the market's price for the default risk.
Fees. Fund charges are almost always quoted in bps, because the differences that matter are smaller than one percent.
What this calculator leaves out
Compounding. It converts a rate into an amount for one period. The example above shows why the multi-year cost of a fee is much larger than the annual figure suggests.
Reading a rate announcement
When a central bank is described as raising rates by 50 basis points, that is half a percentage point on the policy rate, and it passes through to variable mortgages and savings accounts within weeks.
Markets usually price the move before it happens, so the news that shifts prices is the gap between the expected number and the announced one. A 25 bps rise when 50 was expected can push borrowing costs down, which is why the direction of the rate and the direction of the market often disagree on the day.
Negotiating in basis points
On large sums the unit is what makes a negotiation possible. Asking a lender to move from 6.50% to 6.25% sounds like a rounding request; asking for 25 basis points names a quantity both sides price routinely.
On a $350,000 mortgage those 25 bps are about $57 a month and roughly $20,600 over thirty years. Advisory and platform fees are negotiable in the same units, and on a portfolio above a few hundred thousand the annual saving usually exceeds what most people recover by switching funds.
Related calculators
- Expense ratio calculator — what a fund fee removes over a full horizon
- Credit spread calculator — the gap over a risk-free rate
- Percentage calculator — the general conversion