Wizarding Currency Converter — galleons, sickles and knuts

The wizarding currency converter above handles the three-coin money system used in the Harry Potter novels: seventeen silver sickles to one gold galleon, and twenty-nine bronze knuts to one sickle. Those two ratios are the only fixed facts in this tool. Everything else — above all the rate at which a galleon converts into pounds, dollars, euros or anything else — is a number you supply, because the books never give one.

Arb Digital builds free calculators for work and for play, and the discipline is the same in both. State where a figure came from, let the reader change anything that is an assumption, and never dress a guess up as a fact. A fan tool that quietly invented a canonical exchange rate would be doing exactly that, so this one asks you for it instead.

What This Wizarding Currency Converter Does

Pick a direction. Going one way, you enter galleons, sickles and knuts and the tool gives you the total in your own currency at your stated rate. Going the other way, you enter an amount of real money and the tool splits it into whole coins with the remainder shown.

Four supporting figures sit under the headline. The first is the total expressed in knuts, which is the honest base unit of the system and the number worth working in. The second is the same amount tidied into galleons, sickles and knuts with no unit exceeding its ratio. The third and fourth give the value of a single sickle and a single knut at your rate, which is what tells you whether the small change in a scene you are writing is meaningful or trivial.

Both ratios are editable. If you are running a homebrew setting where a galleon is worth twenty sickles, change it and the whole page follows. The defaults are the canonical figures, not a limit.

Where the Ratios Come From

Seventeen sickles to a galleon and twenty-nine knuts to a sickle are stated in the text of the novels by J. K. Rowling, introduced in the Diagon Alley chapter of the first book when Hagrid explains Gringotts money to Harry. They are repeated consistently afterwards and are not a fan invention. One galleon therefore equals 17 × 29 = 493 knuts, which is the single most useful derived number in the system.

What the books do not give is a conversion into real money. There is no scene in which a galleon is priced in pounds sterling, and the various figures that circulate online come from interviews, adaptations, merchandise and fan estimates rather than from the novels. This page takes no position on any of them. It defaults to 5 because a default is needed to make the calculator load populated, and it says clearly in the field hint that the number is yours to replace.

The official Harry Potter and Wizarding World site is the place to check anything you want to treat as canonical, since it is run by the rights holder and is the closest thing to an authoritative reference outside the books themselves.

The Formula / How It's Calculated

Everything reduces to knuts. Total knuts = (galleons × sickles-per-galleon × knuts-per-sickle) + (sickles × knuts-per-sickle) + knuts. With the canonical ratios that is galleons × 493, plus sickles × 29, plus knuts.

Work the default through by hand. Seven galleons is 7 × 493 = 3,451 knuts. Twelve sickles is 12 × 29 = 348 knuts. Add the loose 20 and the total is 3,819 knuts. Divide by 493 and you get 7.7464 galleons, so at a rate of 5 per galleon the amount is 38.73 in your currency. A single sickle is worth 5 ÷ 17 = 0.2941, and a single knut is 5 ÷ 493 = 0.0101.

The reverse direction inverts that. Total knuts = amount ÷ rate × 493, rounded down to a whole knut. Then galleons is the whole-number part of knuts ÷ 493, sickles is the whole-number part of what remains divided by 29, and knuts is what is left after that. Forty units of currency at a rate of 5 is 8 galleons exactly, which is 3,944 knuts, which tidies to 8 galleons, 0 sickles and 0 knuts with nothing over.

The tidying step is ordinary base conversion, just with two irregular bases stacked on each other rather than one regular one. It is the same operation as turning 3,819 seconds into hours, minutes and seconds, except that the divisors are 29 and 17 instead of 60 and 60.

Why a Non-Decimal System Is Harder Than It Looks

Modern readers do arithmetic in base ten without noticing, and a system with divisors of 17 and 29 breaks every instinct that comes with that. You cannot move a decimal point to multiply by ten. You cannot glance at a figure and see roughly what fraction of a galleon it is. Adding two amounts requires carrying at 29 and then again at 17, and both of those are prime numbers, so nothing divides neatly into anything.

This is not a quirk of invented money. Britain used a non-decimal system until 1971, with twelve pence to a shilling and twenty shillings to a pound, and the arithmetic it demanded was a genuine part of school education. The UK National Archives keeps a currency converter for 1270 to 2017 that still takes pounds, shillings and pence as three separate fields, for exactly the reason this calculator does the same. If you have ever wondered why pre-decimal prices look so awkward written down, working through a few conversions here will give you the answer faster than an explanation will.

The practical lesson for anyone writing or running a game in this setting is the one in the tip box: convert to the base unit, do the arithmetic there, convert back once at the end. Doing the carrying in your head at each step is where errors creep in, and they compound.

Using It for Fiction, Games and Classrooms

Writers use a converter like this to keep prices consistent across a long manuscript. If a wand costs seven galleons in chapter three, a butterbeer needs to cost something that feels right against it, and the quickest way to check is to look at both in knuts. Once you see that a galleon is 493 knuts, it becomes obvious that a two-knut sweet and a seven-galleon wand are separated by a factor of about 1,700 — roughly the gap between a boiled sweet and a decent laptop.

Tabletop groups use it to price loot without stopping play. Setting a house rate once at the start of a campaign and writing it on the character sheets removes an argument that otherwise recurs every session. If you run games, the D&D encounter difficulty calculator and the D&D hit points calculator cover the other side of session prep, and the dice roller handles the rolling itself.

Teachers use non-decimal money as a way into modular arithmetic. Asking a class to add 9 galleons 14 sickles 22 knuts to 3 galleons 6 sickles 19 knuts forces genuine carrying at two irregular bases, and it is far more engaging than the same exercise phrased as base conversion. The percentage calculator is useful alongside it when the exercise moves on to discounts and shares.

Choosing a Rate You Can Defend

Because no canonical rate exists, the interesting question is not what the right number is but how to pick one that behaves sensibly in your own setting. Three approaches tend to work.

The first is to anchor on a price. Choose one item whose real-world equivalent you are confident about, decide what it costs in galleons, and let the rate fall out of that division. If a school textbook is a galleon and you think a school textbook costs about thirty units of your currency, your rate is thirty.

The second is to anchor on an income, which is usually more robust. Pick a job, decide what it pays in galleons a year, and compare that with a real salary for the same work. Prices in fiction are often chosen for comic effect; incomes are usually chosen more carefully, so they distort less.

The third is to accept that the source material is internally inconsistent and pick a round number that makes your own scenes work. That is a legitimate choice as long as you make it once and stick to it. Where a story spans decades, the inflation calculator is worth a look before you assume a price from one era transfers to another, and the currency format converter helps if you need amounts written correctly for a different locale.

Handling Fractions and Rounding

Coins are whole things, and a scene in which someone hands over 4.7 knuts does not work. The reverse direction of this tool therefore rounds down to a whole knut and tells you what is left over, rather than quietly rounding to the nearest and losing the difference.

Rounding down is the right default for money you are handing to someone: you cannot pay with a coin you do not have. If you are pricing rather than paying, rounding up may suit you better, and the leftover figure the tool reports gives you what you need to make that adjustment yourself.

The forward direction does not round the coin inputs, because there are legitimate reasons to want half a galleon in a spreadsheet even though there is no such coin. If your inputs are fractional, treat the tidied coin figure as an approximation and the knut total as the exact one.

Common Mistakes to Avoid

• Treating a galleon as 100 knuts. It is 493. The instinct to assume a hundred sub-units comes from decimal currency and does not apply here.
• Carrying at 10 instead of 29 and 17. Adding two amounts requires carrying at twenty-nine into sickles and at seventeen into galleons. Convert to knuts first and the problem disappears.
• Quoting an exchange rate as canon. The novels give no conversion into real money. Any figure you use, including the default here, is an assumption you have chosen.
• Changing the rate mid-project. Prices set under an old rate stop agreeing with prices set under a new one. Fix the rate once and record it.
• Rounding to the nearest coin when paying. You cannot hand over a fraction of a knut. Round down and account for the remainder separately.

Related Free Tools From Arb Digital

Try the unit converter for everyday conversions, the currency format converter for writing amounts correctly in different locales, the inflation calculator when a story spans decades, the percentage calculator for discounts and shares, the dice roller and the D&D encounter difficulty calculator for tabletop sessions, and the D&D hit points calculator for character sheets. The rest is on the free online tools hub.

Frequently Asked Questions

This page is an arithmetic tool for entertainment and educational use. Harry Potter and the Wizarding World are the property of their respective rights holders, and Arb Digital is not affiliated with or endorsed by them. No real exchange rate is published or implied here, and nothing on this page is financial advice.