What a sum will actually be worth calculator

In short

The loss that needs no market move.

Interactive: what a sum will actually be worthEasy

Amount $ Inflation % p.a. Years

Worth then, in today's money: —
Purchasing power lost: —
Amount needed then to match: —
Years to halve: —
Quick check: —
Reading: —

At 2.5% — a central bank's target, not a crisis — money loses about half its purchasing power in 28 years. Set it to 6%, roughly what several developed economies saw in 2022, and the halving arrives in twelve. The rule of 70 in the last line is the mental-arithmetic version, and it is accurate enough for any conversation.

The idea behind it

This calculator belongs to Inflation, where the mechanism it computes is explained step by step, with the formula, what each input means and where the simple model stops being right. Everything is computed in your browser; nothing you type is sent anywhere.

More calculators from Inflation

Fixed versus indexed payments — what escalation is actually worth.
Inflation-linked bond uplift — principal, coupons and the nominal-equivalent yield.

All calculators

Not advice. This explains how something works; it is not a recommendation, and nothing here is tailored to you. You can lose everything you put in — with leveraged instruments, considerably more. StrikeAndYield is not a regulated firm and provides no financial services.

The same in full — six points, and why each one matters

No advice, no recommendation. Nothing on this page constitutes investment, financial, legal, tax or accounting advice, a personal recommendation, or an offer or solicitation to buy or sell any financial instrument.
Nothing here is tailored to you. This is written for a general audience. It does not consider your objectives, financial situation, knowledge, time horizon or tolerance for loss.
The examples are simplified. Worked examples use round numbers and leave out costs, spreads, taxes, collateral, settlement and market conventions that materially change real outcomes.
The models are teaching models. Formulas shown are standard textbook formulations. Institutions add calibration, live market data and credit, funding and capital adjustments — nothing here will reproduce a dealer’s quote or produce a valuation you can rely on.
These instruments carry risk. You can lose your entire investment. Leveraged instruments — futures, options, CFDs, perpetual futures and similar — can cost you considerably more than you originally deposited.
We are not a regulated firm. StrikeAndYield is an independent publication by DELISORIA. It is not a bank, broker, fund manager or licensed adviser, it provides no financial services, and reading it creates no client relationship. For decisions about your own money, consult a professional licensed in your jurisdiction. See the full disclaimer.