Decimals define how many fractional digits your token supports. A supply of 1,000,000 with 6 decimals represents 1 human-readable token — with 9 decimals it represents 0.001 tokens. Decimals are permanent, chosen at mint creation. SOL uses 9, USDC uses 6, most meme coins use 6 or 9.
The Solana token creator asks how many decimals your token should have. Most guides just say "use 9" without explaining what it does or when to pick something else.
For meme coins with billions of supply, use 6 decimals — keeps trader UX simple
For utility tokens paired with SOL frequently, 9 decimals matches SOL for cleaner math
For collectibles or whole-unit tokens (governance vote units), use 0 decimals — no fractions
What this means
Decimals define how many fractional digits your token supports. A supply of 1,000,000 with 6 decimals represents 1 human-readable token — with 9 decimals it represents 0.001 tokens. Decimals are permanent, chosen at mint creation. SOL uses 9, USDC uses 6, most meme coins use 6 or 9.
Step-by-step
For meme coins with billions of supply, use 6 decimals — keeps trader UX simple.
For utility tokens paired with SOL frequently, 9 decimals matches SOL for cleaner math.
For collectibles or whole-unit tokens (governance vote units), use 0 decimals — no fractions.
For stablecoin-style tokens, use 6 to match USDC on Solana.
Confirm your DEX and aggregator display the token with sensible precision before adding LP.
Common mistakes
Choosing 0 decimals for a fungible meme coin — traders cannot buy fractions.
Choosing 18 decimals to "match Ethereum" — unnecessary on Solana, hurts display readability.
Not thinking about decimals × supply interaction — leads to unreadable per-unit prices.