Your average effective and marginal tax rates, and how an extra rand is taxed.
Effective tax rate
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Marginal rate
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Total tax
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Two rates that get confused constantly
Ask most people what tax rate they pay and they will name the rate on their top band, say 31 percent, and assume that is what comes off their whole income. It is not. South Africa taxes income in slices, so only the rand earned in the top band is taxed at the top rate. This tool separates the two numbers that actually matter: your marginal rate, the rate on your next rand, and your effective rate, the share of your total income that tax really takes. Getting them straight changes how you judge a raise, a bonus, or a side gig.
How the slices stack up
The SARS individual scale runs through seven bands. Your first rands are taxed lightly, and each higher slice meets a steeper rate. The bands this calculator applies start at 18 percent, then 26, 31, 36, 39, 41 and 45 percent at the very top, with band edges such as R237,100 and R370,500 marking where each rate kicks in. After the gross tax is added up across the bands, a primary rebate, R17,235 in the figures this tool uses, is subtracted. Those rates and thresholds are the ones to confirm with SARS, but the slice by slice mechanism is the stable part worth understanding.
Splitting R500,000 into its rates
Take a R500,000 taxable income for someone under 65. The income reaches into the 31 percent band, so that is the marginal rate, yet the effective rate is far lower because most of the income sat in cheaper bands and the rebate clawed some back. Here is the breakdown, using the rates this calculator applies.
| Slice of income | Rate | Tax on the slice |
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The three slices sum to R117,507 of gross tax, the rebate trims it to R100,272, and dividing by R500,000 gives an effective rate of 20.05 percent. So while your marginal rate is 31 percent, only about a fifth of your income actually goes to income tax. That spread is the whole point.
The raise myth this kills
The most damaging misunderstanding in personal tax is the fear that earning more pushes your whole income into a higher bracket and leaves you worse off. That never happens under a slice system. A raise is only taxed at your marginal rate on the extra amount, the rands you already earned stay in their old, cheaper bands. So a R20,000 raise at a 31 percent marginal rate costs R6,200 in tax and still leaves R13,800 in your pocket. A practical tip: when weighing a bonus or freelance project, use the marginal rate, not the effective rate, to estimate what you actually keep.
Who finds this most useful
Anyone deciding whether extra work is worth it, negotiating a salary, or simply trying to understand a payslip. It is also handy before making a deductible retirement contribution, because the deduction saves tax at your marginal rate, so a higher marginal rate makes contributing more valuable. Run your own income and age to see exactly where your next rand stands.
Why is my effective rate so much lower than my bracket?
Because the lower bands and the rebate drag it down. Every taxpayer enjoys the 18 percent and 26 percent bands on the first portions of income before any higher rate applies, and the flat primary rebate reduces the final bill regardless of income. The result is that the effective rate climbs slowly and always sits below the marginal rate until income is enormous.
Do rebates change the marginal rate?
No. The rebate is a flat rand amount subtracted after the bands are applied, so it lowers your effective rate and your total tax, but the rate on your next rand is still set by whichever band that rand falls in. Older taxpayers get larger rebates, which is why the tool asks for your age band, but their marginal rate at a given income is unchanged.