--- title: "Investment fee calculator" description: "Compare two annual cost levels over the years you choose: final value, fees paid and the share of the result that higher fees take, in your currency." canonical: "https://investboard.com/calculators/investment-fees" language: "en" modified: "2026-11-09" author: "Investboard" --- # Investment fee calculator What ongoing costs take from your wealth over the years. ## What the calculator answers Ongoing costs are small numbers with a long reach. A fund that charges 1.5% a year and one that charges 0.2% look close on a fact sheet, but the cost is taken every year from a balance that keeps growing, and every amount taken also stops compounding. The calculator puts two cost levels side by side on the same savings path and shows what the higher one takes by the end of the term. You enter a starting amount, a monthly contribution, the term in years, a return before costs, your annual cost and a comparison cost. The result shows the final value at each cost, the fees paid along the way, the share of the final value the higher cost takes and the two paths year by year. Choose your money with **Currency**: the math is the same in every currency, and nothing is converted. ## Which costs belong in the field The annual cost is everything deducted from the portfolio as a percentage each year. For a fund, the starting point is the ongoing charges figure, often called the TER, in its key information document. A fee for advice, a managed account or a platform that is charged as a percentage of the balance belongs in the same figure: it reduces the balance in the same way. Tracking difference, the gap between a fund and its index, is often the more honest measure of what a fund actually costs; how it works is explained in [Understanding ETF costs: TER, tracking difference and hidden fees](/knowledge/understanding-etf-costs). One-off costs, such as an entry charge or an order fee on each purchase, are not a yearly percentage and are not part of the model. ## How the calculator works Both paths start from the same amount and receive the same contributions. They differ only in the cost. The cost is deducted from the annual return, and the net annual rate is turned into a monthly rate: ### Monthly rate after costs ```text Monthly rate = (1 + return − cost)^(1/12) − 1 Example: (1 + 7% − 1.5%)^(1/12) − 1 = 1.055^(1/12) − 1 ≈ 0.447% a month ``` Each month the balance grows at that rate, and the contribution is added at the end of the month. The fees paid are the growth the cost removes, month by month: ### Fees paid in a month ```text Monthly rate before costs = (1 + return)^(1/12) − 1 Fee = balance × (monthly rate before costs − monthly rate after costs) ``` The headline figure is the difference between the two final values. The share puts it in proportion: the difference divided by the larger of the two final values. Starting with 10,000 and adding 300 a month for 20 years at a 7% return before costs, the contributions come to 82,000 on both paths. At 1.5% a year the final value is about 157,837; at 0.2% it is about 186,123. The higher cost takes about 28,286, or 15.2% of the final value. ## Why the gap is larger than the fees On the example inputs, the fees paid come to about 20,000 at 1.5% and about 3,000 at 0.2%. The difference between the final values is still larger, at about 28,286. The reason is compounding: each fee leaves the portfolio, and the growth that amount would have earned over the remaining years leaves with it. The longer the term, the more of the gap comes from that lost growth rather than from the fees themselves. This is also why the share rises with time. A difference of 1.3 percentage points is modest in any single year; over decades it compounds into a meaningful part of the result. ## What the calculator does not model The return before costs is an assumption, not an expected value, and it is held constant. Real markets move unevenly, but that affects both paths in a similar way, so the comparison depends less on the return assumption than the final values do. Tax is not deducted: both final values are before the tax due on selling. Inflation is not deducted either, so the amounts are nominal. Costs are held constant over the whole term, while real fund costs can change. A lower cost says nothing on its own about a fund. Two funds with different costs can follow different indices, carry different risks and earn different returns before costs. The calculator compares two costs on the same return; it does not compare two funds. ## How to read the result Read the headline as what the cost difference takes under the entered assumptions, not as a saving that a switch would deliver. A switch has its own costs, and in many tax systems it means selling the old holding and realizing gains, which can cost more in the year of the switch than the lower fee saves in the first years. Entering the term you actually plan for, and then a lower and a higher return, shows how stable the difference is. Small, frequent costs from trading and adjusting add up in a similar way, as described in [The quiet cost of tinkering](/knowledge/the-quiet-cost-of-tinkering). The calculator shows what the entered costs and return produce. It is not a forecast of any fund's return, not a recommendation to buy, hold or sell a fund and not a tax calculation.