Superannuation Calculator

The Superannuation Calculator projects your Australian super balance to retirement with the features generic retirement calculators miss: the 15% contributions tax applied to concessional contributions before they compound, fund fees netted off your return, an estimate of the personal tax your contributions saved, and a monthly retirement income figure from the projected balance. Contributions can be entered directly, or built from a salary and Superannuation Guarantee rate plus voluntary contributions.

How It Works

$\text{Net Contribution} = \text{Gross Contribution} \times (1 - 0.15) \qquad \text{Net Return} = \text{Return} - \text{Fees}$

$\text{Future Value} = \text{Balance} \times (1+r)^t + \text{Net Contribution} \times \frac{(1+r)^t - 1}{r}$

Only the after-tax contribution compounds — that is the law, not a modeling choice: employer SG and salary-sacrifice contributions are taxed 15% on entry. The tax-savings estimate compares that 15% with an assumed 32% marginal personal rate, crediting each gross contribution dollar with 17 cents saved. Retirement income applies the 4% rule to the final balance: balance × 4% ÷ 12 per month.

The built-in default SG rate is 12%, the statutory rate from 1 July 2025. If you are modeling an earlier period, 11.5% (the 2024–25 rate) remains available in the rate selector.

Worked Example

Age 35 to 60 (25 years), current balance $60,000**, salary **$100,000 with SG at 12%, no voluntary contributions, return 6.5%, fees 0%:

• Gross annual contribution = $100,000 × 12$12,000**; after 15% contributions tax, $10,200 actually compounds
• Growth on the balance: $60,000 × 1.065²⁵ = **$289,663**
• Growth on contributions: $10,200 × ((1.065²⁵ − 1) ÷ 0.065) = **$600,653**
• **Projected balance: $890,316** — from$360,000 of total contributions in (including the starting balance) and $575,316 of investment growth
• **Estimated tax saved on contributions: $51,000** ($12,000 × 25 years × 17%)
• Indicative retirement income: $2,967.72 a month at the 4% drawdown

Note the quiet cost of the contributions tax inside the result: had the full $12,000 compounded untaxed, the balance would be roughly$105,000 higher. The 15% entry tax is the price of the concession, and the $51,000 personal-tax saving is what you bought with it.

Levers That Move the Result

Time dominates: the growth component ($575,316) already exceeds everything contributed, and it grows faster with every added year. Fees are the second lever and the most controllable — a 0.75$30,000 a year including SG at the time of writing) that the projection does not police.

Limitations

Returns are a constant assumption, not a forecast; real fund returns vary year to year and sequencing matters near retirement. The model applies a flat 15% contributions tax and does not include the additional Division 293 tax for incomes above $250,000, contribution cap penalties, insurance premiums deducted from the account, or investment earnings tax nuances inside the fund. Results are nominal dollars, not inflation-adjusted, and the 4% retirement income is a planning convention, not an Age Pension or annuity calculation.

Frequently Asked Questions

Why are my contributions reduced by 15% before compounding?

Because that is what actually happens: concessional contributions are taxed at 15% when they enter your fund, so only 85 cents of each contributed dollar is invested. Projecting the gross amount — as many simple calculators do — overstates the final balance by tens of thousands over a career, as the worked example quantifies.

What return should I assume?

Use your fund's long-term net return for its investment option as the anchor — balanced options have historically returned around 6 to 7% over long periods, growth options more with deeper drawdowns. Then stress-test one point lower: if the plan only works at the optimistic return, the plan is the return assumption, not a plan.

How does the tax-savings figure work?

For each dollar of concessional contribution, you pay 15% inside super instead of your marginal rate outside it. The calculator assumes a 32% marginal rate, so it credits 17 cents per dollar, multiplied across all contributions and years — $51,000 in the example. High earners subject to Division 293 save less; the estimate is a guide, not an assessment.