# Does rounding make retailers money?

No. Symmetric rounding nets to essentially zero — here it is, computed over a real price list rather than asserted.

**Net effect: -0.500¢ per transaction, or -$5.00 per thousand cash sales, slightly favouring the customer. That is a property of the final digits of these 10 particular prices, not of the rounding rule, and it disappears if the price list or the tax rate changes. It is not a strategy.**

| | |
| --- | --- |
| Rule | symmetric |
| Tax rate | 8.25% |
| Transactions | 10 |
| Mean delta per transaction | -0.5¢ |
| Per 1,000 cash sales | -$5.00 |
| Rounded up / down / unchanged | 2 / 6 / 2 |

## Every price

| Price | Exact total | Due in cash | Delta |
| --- | --- | --- | --- |
| $0.99 | $1.07 | $1.05 | -2¢ |
| $1.49 | $1.61 | $1.60 | -1¢ |
| $2.99 | $3.24 | $3.25 | +1¢ |
| $4.99 | $5.40 | $5.40 | 0¢ |
| $7.49 | $8.11 | $8.10 | -1¢ |
| $9.99 | $10.81 | $10.80 | -1¢ |
| $12.99 | $14.06 | $14.05 | -1¢ |
| $19.99 | $21.64 | $21.65 | +1¢ |
| $24.99 | $27.05 | $27.05 | 0¢ |
| $49.99 | $54.11 | $54.10 | -1¢ |

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Canonical URL: https://penny-rounding.gumballtools.com/rounding/does-cash-rounding-make-money
JSON API: `GET https://penny-rounding.gumballtools.com/api/v1/settle?subtotal=19.99&taxRatePercent=8.25`
MCP endpoint: `https://penny-rounding.gumballtools.com/api/mcp`