Currency Converter

Convert between currencies at a rate you set yourself, so historic and broker-specific rates work exactly.

Converting money between two currencies is one multiplication. The difficulty is never the arithmetic — it is knowing which rate to multiply by, and a currency converter that reaches for a live mid-market quote has already made that choice on your behalf, usually wrongly. This one is a manual exchange rate calculator instead: you type the rate, because the rate that applies to a transaction is a fact about that transaction rather than a fact about the interbank market this second.

Formula: converted = amount x rate, with the inverse and any spread shown alongside

Your figures

Amount to convert

In the currency you are converting from.

Exchange rate

Units of the currency you are converting to for one unit of the currency you are converting from. Use the rate that applies to the transaction — the one on the statement, the one fixed for the year, or the one your provider quotes.

Spread or commission

Your bank's, broker's or bureau's mark-up over the rate above, as a percentage. Leave blank when the rate entered is the rate you receive.

Results

Amount received

1,243.75

1,000.00 at an effective rate of 1.24375, in the currency converted to

Rate enteredUnits of the currency converted to, for one unit of the currency converted from.: 1.25000
The same rate invertedOne divided by the rate entered: the same quote read the other way round.: 0.800000
Effective rate after the mark-upThe rate entered less 0.500% of itself. This is the number to compare against a provider who quotes a rate directly rather than a spread.: 1.24375
The effective rate inverted: 0.804020
Mark-up per unit convertedRate entered less effective rate, in the currency converted to.: 0.00625
Converted at the rate enteredBefore the mark-up: what the rate as typed would have produced.: 1,250.00
Cost of the mark-up, converting toThe shortfall, in the currency being converted to.: 6.25
Cost of the mark-up, converting fromThe same shortfall divided by the rate entered, so it reads in the currency being converted from.: 5.00
Mark-up appliedTaken off the rate rather than off the proceeds, which is how it is charged.: 0.500%

What this means

Converting 1,000.00 at 1.25000 gives 1,250.00. A 0.500% mark-up makes the rate actually dealt 1.24375, so 1,243.75 arrives — 6.25 less, which is the same as giving up 5.00 of the amount you started with. The rate entered inverts to 0.800000, which is the identical quote read from the other currency's point of view.

Every rate, spread and mark-up above is yours to enter. No rate is fetched and no bank's or broker's figure is preset — where a field opens with a number it is a round illustration to overwrite, because the rate that applies to a transaction is the one that account is actually dealt at.
The figures are in the two currencies you are converting between, so no currency symbol is shown. The amount received is in the currency converted to; the cost restated in the currency converted from divides by the rate entered, because that is the only rate at which both sides of the transaction agree.
The mark-up is applied to the rate, not deducted from the proceeds. That is how a provider quoting a percentage over the interbank rate actually charges it, and it is what lets a quoted spread and a quoted rate be compared as the same number.
Excludes fixed fees. A transfer charge, a card fee or a minimum commission is a flat amount rather than a percentage of the rate, so it has to be subtracted from the figure above separately.

The link reopens this calculator with the same numbers. Nothing you enter is sent to a server.

Continue with these figures

About the Currency Converter calculation

That single decision is what makes the tool answer the questions people actually open a converter for. Restating an invoice at the rate printed on last March's statement needs a historic rate. Checking what a bank quoting "interbank plus 2%" will really pay needs a rate with a mark-up folded into it. Applying the fixed rate an accountant has set for the financial year needs a rate that deliberately ignores the market. A live feed answers none of the three, which is why this currency conversion calculator treats the rate as an input rather than something to look up.

Enter the amount, the rate, and — if you want it — the mark-up your provider takes as a percentage. The panel returns the amount that actually arrives, the effective rate once that mark-up is folded in, the same quote inverted so you can read it from the other currency's side, and the cost of the mark-up stated twice: once in the currency you receive and once in the currency you started with.

Currency Converter formula

converted at the rate entered = amount × rate
effective rate                = rate × (1 − mark-up ÷ 100)
amount received               = amount × effective rate
mark-up per unit              = rate − effective rate
cost of the mark-up (target)  = converted at the rate entered − amount received
cost of the mark-up (source)  = cost of the mark-up (target) ÷ rate
inverse rate                  = 1 ÷ rate

rate: Units of the currency you are converting to for one unit of the currency you are converting from. A rate of 0.9250 applied to a dollar amount means each dollar buys 0.9250 units of the target currency.
amount: The sum being converted, denominated in the currency you are converting from. It is never touched by the mark-up — the mark-up moves the rate instead.
mark-up: Your bank's, broker's or bureau's charge, expressed as a percentage of the rate. Leave it blank and it is treated as zero, so the rate you typed is the rate you receive.
effective rate: The rate actually dealt once the mark-up has been taken out of it. This is the figure to compare against a provider who quotes a rate directly rather than quoting a spread over something else.
inverse rate: One divided by the rate. It is the identical quote read from the other currency's point of view, and it is the cheapest way to catch a rate entered upside down.

The mark-up is applied to the rate rather than deducted from the proceeds, and that ordering is not cosmetic. A bank quoting "two per cent over the interbank rate" is not levying a separate fee at the end; it is giving you a worse rate from the outset. Expressing the charge as an effective rate is what turns two incomparable quotes into one number: a provider advertising a spread and a provider advertising a rate can finally be put side by side, because both have been reduced to units of the target currency per unit of the source.

The cost is reported in both currencies because the two readings answer genuinely different questions. In the target currency it is the shortfall — the money that did not arrive. In the source currency it is the price of the transaction, the slice of what you handed over that bought nothing. The second figure divides the first by the rate as entered rather than by the effective rate, because the mid is the only rate at which both sides of the trade agree on the value of the same money. Dividing by the dealt rate would overstate the cost, since that rate has already had the mark-up taken out of it — 155.40 euros at 0.9065 comes back as 171.43 dollars rather than the 168.00 actually given up.

The inverse is shown for every conversion because getting a rate the wrong way up is the most common way a conversion goes wrong, and the mistake is invisible in the answer. A rate of 0.9250 and a rate of 1.0811 are the same quote, and multiplying by the wrong one of them gives a number that is neither absurd nor correct. Printing both readings side by side means the error announces itself before the arithmetic runs, rather than after the money has moved.

Currency Converter: a worked example

Settling an 8,400 US dollar supplier invoice from a euro account, using the rate that appeared on the bank statement — 0.9250 euros per dollar — with the bank taking a 2% mark-up on top of it.

Rate entered0.9250 (units of the target currency per unit of the source)
Effective rate0.9250 × (1 − 2 ÷ 100) = 0.9065
Converted at the rate entered8,400 × 0.9250 = 7,770.00
Amount received8,400 × 0.9065 = 7,614.60
Cost of the mark-up, converting to7,770.00 − 7,614.60 = 155.40
Cost of the mark-up, converting from155.40 ÷ 0.9250 = 168.00
Rate inverted1 ÷ 0.9250 = 1.08108

7,614.60 euros arrive rather than the 7,770.00 the quoted rate implies. The 155.40 euro shortfall is the same thing as giving up 168.00 of the 8,400 dollars sent, which is exactly 2% of the amount — the mark-up survives the round trip through the rate unchanged, which is the arithmetic check that the effective rate was built correctly.

How to use the Currency Converter

Enter the amount in the currency you are converting from. It is the sum leaving the account, before anything is deducted.
Enter the rate as units of the currency you are converting to for one unit of the currency you are converting from. If that reading feels ambiguous, check the inverse figure the panel returns: one of the two numbers will obviously be the one you meant.
Used as a historic exchange rate converter, take the rate from the statement, contract or invoice rather than from any quote published today. That is the number an auditor will look for.
Enter the mark-up only when the rate above is a reference rate your provider charges over — an interbank or mid-market rate. If the rate you typed is the rate you are actually being given, leave the mark-up blank so the two figures do not get charged twice.
Read the effective rate rather than the percentage when comparing providers. A bureau quoting a flat rate and a bank quoting a spread become directly comparable once both are expressed that way.
Subtract any fixed fee yourself. A transfer charge or a minimum commission is a flat amount rather than a percentage of the rate, so it sits outside this calculation by design.

Limitations of the Currency Converter

Every calculation makes assumptions. These are the ones that matter here.

Fixed fees are excluded. A wire charge, a card fee or a minimum commission is a flat amount, and on a small conversion it can easily exceed the percentage mark-up entered here.
The mark-up is modelled as a single percentage of the rate. A provider using tiered pricing, or one whose spread widens outside its own dealing hours, will not be described by one number.
No rate is fetched, so this FX conversion calculator cannot tell you whether the rate you typed was a good one on the day. It restates the rate you supply; judging it against the market is a separate exercise.
The result is a spot conversion at a single rate. It does not model a forward contract, a hedged transfer, or a conversion executed in tranches at several different rates.
Rounding conventions vary between providers. A bank settling to the nearest minor unit of the target currency can differ from the figure here by a fraction of a unit on each transaction.

Frequently asked questions about Currency Converter

Why does this currency converter not fetch a live exchange rate?

Because a live mid-market rate answers only one question — what the interbank market is quoting this second — and that is almost never the rate a conversion actually happens at. Historic invoices, accountants' fixed rates and any rate that includes a provider's mark-up all sit outside a feed. Typing the rate covers every one of those cases, and it also means the answer is reproducible: enter the same figures next year and you get the same result.

Should the mark-up be applied to the rate or to the amount?

To the rate, which is what this calculator does, because that is how providers charge it. A percentage of the rate and a percentage of the proceeds happen to give the same money in this simple case, but only the effective rate can be compared against a competitor who quotes a rate directly. That comparison is the reason to express the charge as a rate rather than as a deduction at the end.

What does the inverse rate actually tell me?

It is the same quote read from the other currency's point of view. If the rate you entered says one dollar buys 0.9250 euros, the inverse says one euro buys 1.08108 dollars — identical information, differently arranged. Its practical use is as a sanity check: if the inverse looks like the number you thought you were typing, the rate is in upside down and every figure below it is wrong by that factor.

Why is the cost of the mark-up shown in two currencies?

Because the two readings answer different questions and people ask both. The target-currency figure is what is missing from the money that arrived, which is what a recipient notices. The source-currency figure is what the conversion cost to buy, which is what a budget or a set of accounts needs. They are the same shortfall seen from opposite ends, converted once at the rate entered.

Can I use this for a currency the calculator has never heard of?

Yes, because it never needs to know. There is no currency list anywhere in the arithmetic — the calculator multiplies an amount by a rate, so it works identically for a major pair, an exotic, a token, loyalty points or a historic currency that no longer exists. The only requirement is that you know the rate that applied to the transaction you are describing.

Last reviewed 29 August 2026. See our methodology and editorial policy.

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