Overview

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, Suggest an idea (opens in a pop-up). FAQ, Formulas and About — in the footer and mobile menu. On desktop, the theme, currency, and language switchers plus the Share button are available in both the header and the footer. On the main page, the mobile header stays on one line: calculator name, currency switcher, and menu button. On informational pages, the same top row is followed by a separate «← Back» button below. The mobile menu contains the language switcher, theme toggle, and Share button. The footer also includes navigation, the privacy link, and duplicate theme, currency, language, and Share controls; on mobile they sit on one row, with theme on the left, currency and language centered, and Share on the right.

First visit and quick tour

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.

Start quick tour

Language

The language switcher is available in the header and footer on desktop, and in the mobile menu and footer on mobile. It lets you choose the 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

The theme toggle (sun/moon icon) lets you choose the light or dark theme: in the header and footer on desktop, and in the mobile menu footer plus the page footer on mobile. Your choice is saved and restored on the next visit.

Currency

The currency switcher is available in both the header and the footer, and lets you display amounts in any currency from central bank rates. The dropdown shows the country flag, currency code, and symbol. Popular currencies (euro, dollar, ruble, hryvnia, Belarusian ruble) are pinned at the top. Search works by code («usd», «eur»), by currency name, and by country — in Russian and English (for example «usa», «dollar», «ukraine», «belarus»). Arrow keys navigate the list, Enter selects.

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).

On desktop, the Share button is available in both the header and the footer; on mobile, it is available in the menu and in the footer. It copies a link with the current calculator parameters. Paste it into chat or social media — the recipient will see your scenario (amounts, term, rate, and so on). On mobile, the native share menu may appear.

Install on phone

The calculator supports PWA — you can add it to your phone's home screen and use it offline. In the browser (Chrome, Safari, Samsung Internet) tap «Add to Home Screen» or «Install app» in the menu. Once installed, the app opens without the address bar and works without internet (currency rates and inflation API update only when online).

Passive income planning

In Savings forecast mode the block lets you enter date of birth and retirement age (55, 60, 65 or another value). The savings term updates automatically when these fields change. The current retirement age is shown to the right of the slider, next to the checkmark. If you manually changed the term with the slider, click the checkmark to reapply the calculated term.

Savings forecast

Initial amount — money at the start of the calculation: on account, on deposit, or cash you're ready to invest.
Monthly contribution — regular deposit each month. Contribution mode: Fixed amount — same nominal amount each month; Index to inflation — base amount in today's money, nominal grows with inflation, real value stays constant. Useful for long-term planning (retirement, major goal). On mobile, the mode switcher sits on its own line under “Mode” so both options stay fully visible.
Return rate — expected annual return in %. For stocks typically 12–22%, for conservative instruments (bonds, deposits) — 14–18% at key rate ~15%
Term — number of years saving
Inflation — money depreciation. Real growth = nominal minus inflation. Typically 5–8% per year
One-time contributions — extra amounts in specific months (bonus, inheritance). Shown on chart as a vertical jump at contribution moment.

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.

Goal calculator

Enter target amount and parameters. Two calculation modes:

When will I reach my goal? — with known contribution, calculates term
How much to save? — with known term, calculates monthly contribution. Term set in months (slider 1–480), displayed in years and months in Total block.
One-time contributions — extra amounts in specific months (bonus, windfall). Also available in Goal calculator.

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). On mobile, this switcher also sits on its own line under “Mode”.

«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.

Interface elements

The page is divided into two sections: Parameters — what you enter (amounts, rates, term), and Results — calculated values, chart, and table.

Scale — X-axis label format: calendar dates or years/months from start. On mobile, the label and tooltip sit above the switcher, and the switcher itself stretches to the full block width.
Granularity — point step: yearly, quarterly or monthly. On mobile, this switcher follows the same pattern: label above, full-width buttons, matching button height.
«Composition» chart — shows components: initial capital, contributions, accumulated interest; dashed «Cash with inflation adjustment» — real value when holding cash. On hover — safe spending amount per period
Passive income and safe withdrawal — income from capital at end of term, breakdown into inflation compensation and real income, safe monthly spending amount
Period breakdown — table of contributions and income per period; with indexed contributions — «Contribution in period» column grows with inflation; with rate and inflation — «Income above inflation» column (monthly real income); with inflation — «Balance in nominal» and «Real value»

Tips

Hover over elements — a short tooltip appears. Fields have ⓘ icon — hover for description and calculation formula.

Formulas

Term definitions and calculation formulas — on a separate Formulas page.

Data and privacy

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.