Net yield on an investment after platform and fund fees.

A fund quoting a 5% yield with a 0.3% platform fee and a 0.75% OCF pays an effective 3.95% net. Over a decade on 100,000 that's 11,200 less than the headline number implies. Fees erode returns silently — this tool makes the actual drag visible.

What the result means

Primary is net yield after all deducted fees. Secondary shows total fee drag, platform fee, and fund fee separately. The gap between gross and net is the cost of being invested through this structure — it compounds meaningfully over 10+ year horizons.

Why fees matter more than they look

A 1% fee sounds small. Over 30 years on a growing portfolio, a 1% fee drag removes roughly 25-30% of the final value versus a fee-free alternative. Fees compound against you the same way returns compound in your favour — which is why low-cost passive investing has become popular for long-horizon investors.

A worked example

Try the defaults: gross yield of 5%, platform fee of 0.3%, fund ocf of 0.75%. The tool returns 3.95%. You can adjust any input and the result updates as you type — no submit button, no reload. That's the real power here: seeing how sensitive the output is to one or two assumptions.

What moves the number most

The result responds to Gross Yield, Platform Fee, and Fund OCF. Frequency and unit price pull the total in different directions. The biggest surprise for most people is how small recurring amounts compound into large annual figures — that's where this calculation earns its keep.

The formula behind this

Simple subtraction — platform and fund fees are usually quoted as percentages of assets annually, so they subtract directly from yield. For transaction-based fees (dealing charges, spreads) divide estimated annual cost by portfolio value to convert to a percentage before adding. Everything the calculator does is shown in the formula box below, so you can check the math against your own spreadsheet if you want.

Where this fits in planning

This is a "what-if" tool, not a forecast. Use it to test ideas before committing: what happens if the rate is 2% lower than hoped, what happens if you add five more years. The value is in the scenarios you run, not the single answer you get from the defaults.

What this doesn't capture

Steady-rate math ignores real-world volatility. Actual returns are lumpy; sequence-of-returns risk matters most in drawdown; fees and taxes drag on compound growth; and behaviour changes in drawdowns can reduce outcomes below the projection. Treat the number as one scenario, not a forecast.