Currency Converter
Convert between the euro and every legacy national currency at the irrevocable rates fixed by EU law — using the legally mandated triangulation algorithm, not the inverse rates that Regulation 1103/97 expressly forbids.
Currency Converter
Results recalculate instantly on every keystroke. Nothing you type is transmitted.
What this result does not account for
- No live or market exchange rates — by design, since the page makes no network request.
- Covers only currencies replaced by the euro at a legally fixed rate.
- Physical note redemption deadlines have expired in several countries; the rate remains valid but the cash may not.
- Article 5 rounding applies to amounts payable, not to unit tariffs or intermediate computations, which expect higher precision.
In short: This page does not quote live exchange rates, and it will not pretend to. It runs entirely in your browser with no server, so any ‘live’ figure it showed would be stale the moment it loaded. What it does instead is the conversion that never changes: the irrevocably fixed euro rates of Council Regulation 2866/98 — 1 EUR = 1.95583 DEM = 6.55957 FRF = 1,936.27 ITL — applying the Article 4(4) triangulation required by law.
Formula
Council Regulation (EC) No 1103/97 sets the algorithm; Council Regulation (EC) No 2866/98 sets the rates. Neither has been amended in substance.
Worked Example
- Divide into euro. 100 DEM ÷ 1.95583 = 51.129188... EUR.
- Keep the precision. Article 4(4) allows rounding here to no fewer than three decimals.
- Multiply out. 51.129188 × 6.55957 = 335.386... FRF.
- Round under Article 5. To the nearest sub-unit, halves upward → FRF 335.39.
- Never invert. Multiplying by a rounded reciprocal is expressly prohibited.
Twelve cents out of thin air. Take one million German marks. The lawful method divides by 1.95583 and gives EUR 511,291.88. The forbidden method takes the reciprocal of the rate, rounds it to the same six significant figures the regulation uses — 0.511292 — multiplies, and gives EUR 511,292.00. The gap is about twelve cents, invented purely by rounding the rate before using it. On a single transfer nobody would notice; across a clearing bank's daily settlement it is a systematic drift in one direction, which is exactly why Article 4(3) bans the shortcut outright rather than merely discouraging it. This is also the clearest illustration of why the regulation insists the rate itself is never rounded or truncated during a conversion.
Strengths & Limits Of This Model
Where this engine is strong
- States plainly that it has no live rates rather than showing a stale number as though it were current.
- Implements the legally mandated triangulation and the prohibition on inverse rates, with the arithmetic shown.
- Rates are quoted at the exact six significant figures adopted by regulation.
Where it stops
- Cannot help with dollar, pound, yen or rupee conversion.
- Not a substitute for a bank quotation on a live transaction.
- Historical purchasing power is a separate question from nominal conversion.
Practical Use Cases
Restating historical accounts
Converting pre-euro figures into euro on the legally correct basis for audit and comparative reporting.
Valuing old banknotes and coins
Establishing the euro value of legacy currency, though redemption deadlines have passed in several countries.
Legacy system migration
Implementing or verifying the Article 4(4) triangulation algorithm against a reference calculation.
Reading historical prices
Understanding what a price in lira or francs meant — pair with the Inflation Calculator to restate it in today’s money.
Methodology & Editorial Standards
This converter implements Council Regulation (EC) No 1103/97 exactly. Rates are those adopted in Council Regulation (EC) No 2866/98 and the subsequent accession regulations, each stated as units of national currency per one euro with six significant figures. Conversion between two national currencies follows the Article 4(4) triangulation: the source amount is divided by its rate to give an amount in euro, which may be rounded to no fewer than three decimals, and that amount is multiplied by the target rate. Inverse rates are never used, in compliance with Article 4(3), and the rates themselves are never rounded or truncated during conversion, in compliance with Article 4(2). Final amounts are rounded under Article 5 to the nearest sub-unit with exact halves rounded up; for currencies whose sub-unit had fallen out of practical use, such as the lira and the drachma, the result is rounded to the nearest whole unit. This page performs no network request and holds no market exchange rate data of any kind. All conversion factors are exact by definition under the International System of Units, or exact by international agreement where the unit is defined by treaty. Values are held at full IEEE-754 double precision internally and rounded only for display, so chained conversions do not accumulate drift.
Computation runs in IEEE-754 double precision at full internal precision; rounding to two decimal places occurs strictly at the display layer, so no cumulative drift enters the result. All monetary outputs use accounting presentation — grouped thousands, two decimals, negatives in parentheses — so figures can be transcribed directly into a model or working paper. Division-by-zero and out-of-domain inputs return an em-dash rather than a misleading number.
This engine was reconciled against an independent reference implementation and hand-verified for the worked example above before release. Our full five-stage review process is published on the About Us page.
Disclaimer. This calculator is provided for informational and modelling purposes only and does not constitute financial, tax, legal, medical, or engineering advice. Verify all figures with a qualified professional before acting on them.
Currency Converter — 8 Expert FAQs
8 analyst-written answers to the questions practitioners actually ask — optimised for voice and answer-engine retrieval.
Why doesn't this converter show live exchange rates?
Because it runs entirely in your browser with no server, which is what keeps your data private, and a cached market rate would be wrong within minutes of loading. Rather than display a stale number dressed up as live, the page converts only rates that are fixed permanently by law. For a live trade, use the rate your own bank or broker quotes at the moment of dealing.
What is an irrevocable conversion rate?
It is a legal definition rather than a market price. When a country adopted the euro, the Council fixed the rate between the euro and that currency permanently, with six significant figures. The two are then simply the same value written two ways, so the rate carries no spread, no bid and offer, and no expiry, and it cannot move regardless of market conditions.
Why can't I just multiply by the inverse rate?
Because Article 4(3) of Regulation 1103/97 forbids it, for a concrete arithmetic reason. The reciprocal of 1.95583 is 0.51129188..., and any rounded version of that introduces an error that always leans the same way. On a million marks the shortcut invents about twelve cents. Across settlement volumes those cents accumulate systematically, so the regulation requires division by the published rate.
What is triangulation?
The mandatory two-step route between two legacy currencies: convert the source amount into euro first, then convert that euro amount into the target currency. Direct cross-rates between national currencies were never published, precisely so that everyone would compute the same answer. Article 4(4) permits no alternative method unless it provably gives identical results.
What does six significant figures mean here?
Six figures counted from the first non-zero digit, which is not the same as six decimal places. The Italian lira rate is 1936.27 with two decimals, the Irish pound rate is 0.787564 with six, and the German rate 1.95583 with five — all three carry exactly six significant figures. Article 4(2) then forbids rounding or truncating them further when converting.
Can I still exchange old banknotes for euro?
It depends entirely on the country. Germany exchanges Deutsche Mark indefinitely and free of charge at the Bundesbank. Ireland, Austria, Spain and several others also have no deadline. But the Italian lira, the Greek drachma, the French franc and the Portuguese escudo have all passed their final redemption dates, and those notes can no longer be converted into euro at any central bank.
Why did Bulgaria join at the same rate as Germany?
Coincidence of policy rather than of arithmetic. The Bulgarian lev was pegged to the Deutsche Mark at parity in 1997 under a currency board, and when the mark was replaced the peg simply carried over to the euro at 1.95583. Bulgaria adopted the euro on 1 January 2026 at exactly that long-standing rate, so the changeover involved no revaluation at all.
How should an exact half be rounded?
Upward. Article 5 states that where applying the conversion rate produces a result exactly half-way between two sub-units, the sum is rounded up. This is a deliberate departure from banker's rounding, which would round to the nearest even value, and it was chosen so that every party computing the same conversion arrives at precisely the same figure.