Hong Life CalculatorsUnderstanding the D&D coin converter — concept and principle
Dungeons & Dragons uses five coins: copper, silver, electrum, gold and platinum. This calculator adds up a pile of mixed coins, shows its total value in gold, copper, silver and platinum, works out the fewest coins that make the same value and tells you how much your current coins weigh.
How it is calculated
Total in copper = pp × 1,000 + gp × 100 + ep × 50 + sp × 10 + cp
Total in gp = copper ÷ 100; in sp = copper ÷ 10; in pp = copper ÷ 1,000
Fewest coins: platinum = ⌊copper ÷ 1,000⌋, then gold, silver and copper from the remainder
Weight = number of coins ÷ 50 (lb); kg = lb × 0.45359237
- Exchange rates from the SRD: 10 cp = 1 sp, 10 sp = 1 gp, 2 ep = 1 gp, 10 gp = 1 pp.
The principle
Converting everything to the smallest unit, copper, makes adding easy because every coin becomes a whole number of copper pieces. To find the fewest coins, you use the largest coins first and carry the remainder down, just as you would make change with real money. Electrum (half a gold piece) is never needed for the fewest coins, because two electrum are worth one gold coin and one electrum is worth five silver, so gold and silver always do at least as well. The SRD says a standard coin weighs about a third of an ounce, so 50 coins make a pound.
Worked example
Default inputs: 3 pp, 47 gp, 2 ep, 15 sp, 28 cp.
- Copper total = 3,000 + 4,700 + 100 + 150 + 28 = 7,978 cp.
- Value = 79.78 gp = 797.8 sp = 7.978 pp.
- Fewest coins: 7 pp, remainder 978 → 9 gp, remainder 78 → 7 sp, remainder 8 cp.
- That is 31 coins after exchanging, compared with the 95 you carry now.
- Weight now = 95 ÷ 50 = 1.9 lb = 0.86 kg.
| Copper pieces (cp) | Total value (gp) |
|---|---|
| 7 | 79.57 |
| 14 | 79.64 |
| 21 | 79.71 |
| 28 | 79.78 |
| 35 | 79.85 |
| 42 | 79.92 |
| 56 | 80.06 |
How to read the result
Exchanging to fewer, larger coins saves weight, which matters if your table tracks encumbrance. In some campaigns, money changers charge a fee for exchanges, and large coins can be awkward to spend in small villages, so the fewest-coins result is a convenience, not a rule. Treasure hoards are often listed in gp value, which you can compare directly with the total here.
Common mistakes
- Treating electrum as worth 5 gp instead of half a gold piece.
- Forgetting that 1 pp equals 10 gp, not 100.
- Ignoring coin weight in games that use encumbrance.
Frequently asked questions
How many copper pieces are in a gold piece?
100 copper pieces.
What is an electrum piece worth?
Half a gold piece, or 5 silver pieces.
How much do 1,000 coins weigh?
20 lb, at 50 coins per pound.
Why does the calculator skip electrum in the fewest coins?
Gold and silver can always make the same value with no more coins.
Sources: This page includes material from the System Reference Document 5.2.1 ("SRD 5.2.1") by Wizards of the Coast LLC, licensed under the Creative Commons Attribution 4.0 International License (CC-BY-4.0). Section used: Equipment, "Coins".