{"success":true,"version":"v1","request":{"tool":"get_calculator_schema","calculator_id":"expense-ratio-impact"},"result":{"entity_type":"calculator","id":"expense-ratio-impact","calculator_id":"expense-ratio-impact","canonical_url":"https://tttkmbb.com/investing/expense-ratio-impact","name":"Expense Ratio Impact Calculator","title":"Expense Ratio Impact Calculator – Long-Term Cost of Fund Fees on a Growing Investment","category":"investing","category_name":"Investing & Real Estate","tool_name":"calculate_expense_ratio_impact","featured_mcp_tool":false,"description":"Grows an initial investment with optional annual contributions at a gross return minus a fund's expense ratio, compares it with a lower-cost alternative, and reports the total fee cost and its share of the final value.","use_when":"You want to see how much a fund's annual expense ratio costs over decades, or compare two funds with different fees on the same investment plan.","do_not_use_when":"You need a plain growth projection without fees (use compound-interest) or a comparison including loads, trading costs and taxes. Informational only; not financial advice.","inputs":[{"name":"initial_investment","label":"Initial investment","type":"number","required":true,"min":0,"max":1000000000000,"description":"Amount invested at the start.","example":10000},{"name":"annual_contribution","label":"Annual contribution","type":"number","required":false,"default":0,"min":0,"max":10000000000,"description":"Amount added at the end of each year.","example":0},{"name":"years","label":"Years","type":"integer","unit":"years","required":true,"min":1,"max":100,"description":"Investment horizon.","example":30},{"name":"annual_return_percent","label":"Gross annual return","type":"number","unit":"% per year","required":true,"min":-50,"max":100,"description":"Expected return of the underlying assets before fees.","example":7},{"name":"expense_ratio_percent","label":"Expense ratio","type":"number","unit":"% per year","required":true,"min":0,"max":20,"description":"Annual fund fee as a percent of assets (e.g. 1 for 1.00 %).","example":1},{"name":"comparison_expense_ratio_percent","label":"Comparison expense ratio","type":"number","unit":"% per year","required":false,"default":0,"min":0,"max":20,"description":"Fee of the alternative fund; 0 shows the cost against a fee-free benchmark.","example":0}],"outputs":[{"name":"total_contributions","label":"Total amount invested","type":"number","decimals":2,"description":"initial_investment + annual_contribution × years."},{"name":"final_value_with_fees","label":"Final value with the expense ratio","type":"number","decimals":2,"description":"Value after `years` at the net return (gross − expense ratio)."},{"name":"final_value_with_comparison","label":"Final value at the comparison fee","type":"number","decimals":2,"description":"Same plan at gross − comparison_expense_ratio."},{"name":"total_fee_cost","label":"Cost of the higher fee","type":"number","decimals":2,"description":"final_value_with_comparison − final_value_with_fees (fees paid plus the growth they would have earned)."},{"name":"fee_cost_percent_of_final","label":"Fee cost as % of the comparison value","type":"number","unit":"%","decimals":2,"description":"total_fee_cost / final_value_with_comparison × 100."},{"name":"effective_annual_return_percent","label":"Net annual return","type":"number","unit":"%","decimals":2,"description":"annual_return_percent − expense_ratio_percent."}],"input_schema":{"type":"object","properties":{"initial_investment":{"description":"Amount invested at the start.","type":"number","minimum":0,"maximum":1000000000000,"examples":[10000]},"annual_contribution":{"description":"Amount added at the end of each year.","type":"number","minimum":0,"maximum":10000000000,"default":0,"examples":[0]},"years":{"description":"Investment horizon. Unit: years.","type":"integer","minimum":1,"maximum":100,"examples":[30],"x-unit":"years"},"annual_return_percent":{"description":"Expected return of the underlying assets before fees. Unit: % per year.","type":"number","minimum":-50,"maximum":100,"examples":[7],"x-unit":"% per year"},"expense_ratio_percent":{"description":"Annual fund fee as a percent of assets (e.g. 1 for 1.00 %). Unit: % per year.","type":"number","minimum":0,"maximum":20,"examples":[1],"x-unit":"% per year"},"comparison_expense_ratio_percent":{"description":"Fee of the alternative fund; 0 shows the cost against a fee-free benchmark. Unit: % per year.","type":"number","minimum":0,"maximum":20,"default":0,"examples":[0],"x-unit":"% per year"}},"additionalProperties":false,"required":["initial_investment","years","annual_return_percent","expense_ratio_percent"]},"output_schema":{"type":"object","properties":{"total_contributions":{"description":"initial_investment + annual_contribution × years.","type":"number"},"final_value_with_fees":{"description":"Value after `years` at the net return (gross − expense ratio).","type":"number"},"final_value_with_comparison":{"description":"Same plan at gross − comparison_expense_ratio.","type":"number"},"total_fee_cost":{"description":"final_value_with_comparison − final_value_with_fees (fees paid plus the growth they would have earned).","type":"number"},"fee_cost_percent_of_final":{"description":"total_fee_cost / final_value_with_comparison × 100. Unit: %.","type":"number","x-unit":"%"},"effective_annual_return_percent":{"description":"annual_return_percent − expense_ratio_percent. Unit: %.","type":"number","x-unit":"%"}}},"formula":"net = (annual_return_percent − expense_ratio_percent)/100; V_0 = initial_investment; V_t = V_{t−1} × (1 + net) + annual_contribution; final_value_with_fees = V_years; the comparison uses comparison_expense_ratio_percent; total_fee_cost = final_value_with_comparison − final_value_with_fees","method":"Fees are modelled as a constant reduction of the annual return (the SEC's Investor.gov illustration uses the same approach); contributions are made at the end of each year and returns are assumed constant. Informational mathematics only; not financial advice.","sources":[{"name":"Investor.gov (U.S. SEC) – Understanding Fees","url":"https://www.investor.gov/introduction-investing/getting-started/understanding-fees","type":"government","retrieved_at":"2026-09-24"},{"name":"Wikipedia – Expense ratio","url":"https://en.wikipedia.org/wiki/Expense_ratio","type":"reference","retrieved_at":"2026-09-24"}],"freshness":{"type":"static","max_age_seconds":null,"note":"Deterministic formula with fixed constants; results never go stale. Inputs supplied by the caller determine the output."},"examples":[{"name":"10,000 for 30 years at 7 %, 1 % fee vs no fee","inputs":{"initial_investment":10000,"years":30,"annual_return_percent":7,"expense_ratio_percent":1},"expected":{"total_contributions":10000,"final_value_with_fees":57434.91,"final_value_with_comparison":76122.55,"total_fee_cost":18687.64,"fee_cost_percent_of_final":24.55,"effective_annual_return_percent":6},"url":"https://tttkmbb.com/api/v1/calculate/expense-ratio-impact?initial_investment=10000&years=30&annual_return_percent=7&expense_ratio_percent=1"},{"name":"50,000 plus 6,000 a year for 25 years at 8 %, 0.75 % vs 0.05 %","inputs":{"initial_investment":50000,"annual_contribution":6000,"years":25,"annual_return_percent":8,"expense_ratio_percent":0.75,"comparison_expense_ratio_percent":0.05},"expected":{"total_contributions":200000,"final_value_with_fees":681068.81,"final_value_with_comparison":773927.69,"total_fee_cost":92858.87,"fee_cost_percent_of_final":12,"effective_annual_return_percent":7.25},"url":"https://tttkmbb.com/api/v1/calculate/expense-ratio-impact?initial_investment=50000&annual_contribution=6000&years=25&annual_return_percent=8&expense_ratio_percent=0.75&comparison_expense_ratio_percent=0.05"}],"faq":[{"q":"Why does a 1 % fee cost about a quarter of the final value?","a":"The fee is charged every year on the whole balance, and the money taken out stops compounding; over 30 years at 7 % the balance at 6 % net ends 24.5 % lower."},{"q":"Is the fee subtracted from the return exactly?","a":"Nearly: funds accrue the expense ratio daily on assets, which is very close to lowering the annual return by the ratio. Trading costs inside the fund and any sales loads are extra."}],"tags":["expense ratio","fund fees","cost of fees","management fee impact","index fund vs active fund","fee drag"],"related":[{"calculator_id":"compound-interest","reason":"Growth of the same plan without fees."},{"calculator_id":"retirement-savings","reason":"Full retirement projection with contributions."},{"calculator_id":"cagr","reason":"Annualized return implied by two values."}],"links":{"html":"https://tttkmbb.com/investing/expense-ratio-impact","markdown":"https://tttkmbb.com/investing/expense-ratio-impact.md","json":"https://tttkmbb.com/investing/expense-ratio-impact.json","api":"https://tttkmbb.com/api/v1/calculate/expense-ratio-impact","schema":"https://tttkmbb.com/api/v1/calculators/expense-ratio-impact","openapi":"https://tttkmbb.com/openapi.json","mcp":"https://tttkmbb.com/mcp"},"version":"v1","updated_at":"2026-09-24"},"timestamp":"2026-09-24T03:48:40Z"}