How to use the calculator
Calculator helps estimate savings growth with compound interest and inflation. Two modes: Savings forecast — simulation over time; Goal calculator — calculate term or monthly contribution to reach a goal. Header and nav: Quick tour, Help, FAQ, About. Theme, currency, language switchers, Share button — in header. Footer — nav and privacy link.
On first visit, an interactive tour shows Savings forecast fields (date of birth, initial amount, return rate, term, contribution, inflation), results, then Goal calculator (target amount, calculation modes, results). You can step through or dismiss. Quick tour — in the nav under the header, in the mobile menu, or in the footer. Also via ?tour=1 link.
Language switcher (in header) lets you choose interface language: Russian, English, French, or Spanish. When you switch, the URL changes (e.g. /ru/ or /en/) — you can share a link in the desired language. Number formats, dates and chart labels update automatically.
Theme toggle (sun/moon icon in header) lets you choose light or dark theme. Choice is saved and restored on next visit.
Currency switcher (in header next to Help) lets you display amounts in any currency from central bank rates. Dropdown shows country flag, currency code and symbol. Popular currencies (euro, dollar, ruble, hryvnia, Belarusian ruble) at top. Search works by code («usd», «eur»), by currency name and by country — in Russian and English (e.g. «usa», «dollar», «ukraine», «belarus»). Arrow keys — navigate list, Enter — select.
On first currency switch, values are converted at current rate. When returning to a previously selected currency, cached values are restored — no reconversion, so rounding and rate changes don't «drift» figures.
Inflation refresh button (next to Inflation field) applies current annual inflation: for ruble — from official statistics; for other currencies — from central banks (source: statbureau.org).
The Share button (in header next to currency) copies a link with current calculator parameters. Paste it in chat or social — the recipient will see your scenario (amounts, term, rate, etc.). On mobile, the native share menu may appear.
In Savings forecast mode the block lets you enter date of birth and retirement age (55, 60, 65 or other). Savings term is applied automatically when these fields change. If you manually changed the term with the slider, click the checkmark next to retirement age to reapply the calculated term.
As of March 2026. Key rate and inflation change — consider current situation in calculations.
Chart shows nominal growth (account balance), real value (in today's money), contribution sum and «Cash with inflation adjustment» line — real value of sum if held as cash without interest. Shows how inflation eats savings: each month, each year purchasing power drops.
Passive income and safe withdrawal block shows income from capital at end of term and breakdown. Passive income (nominal) — figures on account. Inflation compensation — part of income to keep on account so capital purchasing power doesn't fall. Safe to spend — how much you can spend so inflation doesn't erode savings. In block — value at end of term; hover on chart and in breakdown table — per period.
Results block also shows: ROI — return on invested capital; Income share — % of total earned by compound interest; Gain vs cash — how much more in real terms than storing under mattress; Capital doubling — approximate time to double real value (Rule of 72). Passive income block can be collapsed.
Enter target amount and parameters. Two calculation modes:
Goal in nominal — amount that will be on account in future. Goal in real terms — adjusted for inflation, how much that would be in today's money.
Contributions: Fixed amount — same nominal amount each month. Index to inflation — base amount in today's money, nominal grows with inflation. In «How much to save?» mode with indexing, result is base contribution (first month — this amount, then — more by inflation).
«Cash with inflation adjustment» line shows how the sum would change if you saved in cash (no deposit or instruments). In real terms — adjusted for inflation: see how inflation eats your savings each month and year.
When goal is reachable, results block shows: nominal and real total on account, real return, ROI, and After reaching goal block — passive income and safe monthly spending upon reaching the goal.
The page is divided into two sections: Parameters — what you enter (amounts, rates, term), and Results — calculated values, chart, and table.
Hover over elements — a short tooltip appears. Fields have ⓘ icon — hover for description and calculation formula.
On first visit, a notice about local storage of settings (theme, calculation parameters, currency, custom contributions) appears at the bottom of the page. The «Got it» button dismisses it. For details on what data is stored and how to remove it — see the Privacy Policy.