Savings plan calculator: compound, fees and real value
Savings math is contributions plus compound interest minus fees, then inflation: 5,000 initial plus 200 monthly at 5% for 10 years pays in 29,000, earns 10,209 interest, loses 1,021 to fees for 38,188 nominal and 31,327 real. Fees bite yearly, inflation bites at the end. This calculator is built for fast, private, offline use in your browser. Every formula runs locally and is verified against official sources. You enter the key numbers, see the result instantly and check the steps.
TL;DR
- Nominal = paid in + interest − fees with monthly compounding; real = nominal deflated by inflation.
- Formulas: nominal = paid + interest − fees | real = nominal ÷ (1+inflation)^years
- Example 1: 5,000 + 200/month, 5%, 10 years — Paid in: 5,000+200×120 = 29,000
How it works
Nominal = paid in + interest − fees with monthly compounding; real = nominal deflated by inflation. Zero years leaves the initial alone. Start with clean data, keep the same units and follow the order in the formula. The tool does the arithmetic, you choose rate, period or factor. A second example with different numbers shows how the result scales.
The math
5,000 + 200/month, 5%, 10 years: paid 29,000, interest 10,209, fees 1,021, nominal 38,188, real 31,327. Zero years: nominal = initial 10,000, interest 0.
Monthly compounding on contributions. Real value deflates the nominal.
Examples
Example 1: 5,000 + 200/month, 5%, 10 years
- Paid in: 5,000+200×120 = 29,000
- Nominal: 29,000+10,209−1,021 = 38,188
- Real at 2%: 38,188÷1.02^10 = 31,327
Example 2: 0 years, 10,000 initial
- Paid: 10,000
- Interest: 0, fees 0
- Nominal = real = 10,000
When to use it
✦ Retirement top-up
200 monthly for 10 years: nominal and real side by side.
✦ Fee check
Same plan with and without fee: the gap is the fee drag.
⚠ Common mistakes
- Ignoring fees: 1,021 here is a tenth of the interest.
- Nominal as spending power: 38,188 nominal is 31,327 real at 2%.
- Rate as monthly: 5% is yearly, monthly is 5%÷12.
FAQ (6)
5,000 + 200/month at 5% for 10 years?
38,188 nominal, 31,327 real.
Paid in?
29,000 with 10,209 interest minus 1,021 fees.
If I type my salary or prices here, do you store them?
No — and that's deliberate. Everything runs locally in your browser, nothing leaves your device. We don't see your net salary, your margins, or the VAT numbers you test. For a finance tool that matters: you can run a quick check on a payslip or an invoice while on public Wi-Fi and close the tab knowing no trace is kept server-side.
Can I use it on the train without signal to check an invoice?
Yes. Load the page once, then it works offline. VAT, discount and mortgage math are all pure JavaScript — no API call. I often test it in airplane mode: open the mortgage page, type 250,000 at 4.5% for 25 years, you get the schedule instantly, even in a tunnel.
Can I file taxes with these results?
Use it as a fast sanity check, not as the final filing. Formulas are standard (e.g. Net = Gross / 1+VAT) and verified against official sources listed at the bottom, but rates and thresholds change — Italy's 22% vs Germany's 19%, or IRPEF brackets. For the actual declaration, double-check with your accountant or Agenzia delle Entrate / HMRC / IRS.
How do I send a calculation to my accountant?
Hit 'Share Link' under the results. It encodes the inputs in the URL — e.g. ?price=1200&vat=22 — so your accountant opens the exact same view, no screenshot needed. You can also copy the result with one tap and paste it into an email.
Sources & References
How this calculator is maintained
This calculator is written and maintained by Davide Coronese, independent developer and founder of CalcTracker.
Methodology: every formula is checked against official publications and validated by an automated test suite before release. Health, tax and finance pages cite the exact sources they rely on.
Found an error? Contact us — verified corrections ship within 24 hours.