Guide · 4 min read
Fixed vs floating exchange rates: which should you pick?
By the AltoSwap team · Reviewed and updated · Editorial policy
Short answerA floating rate is calculated when your deposit is confirmed, so you receive the market rate at that moment. This is usually the better deal, but the final amount can differ from the estimate. A fixed rate locks the amount you receive for a short window in exchange for a slightly wider spread. Choose floating for the best expected value on fast, liquid pairs; choose fixed when you must receive an exact amount or the market is moving quickly.
How a floating rate works
With a floating rate, the quote you see is an estimate based on the current market. The actual conversion happens when your deposit reaches the required number of confirmations. If the market moved in your favour in the meantime, you receive more; if it moved against you, you receive less.
Because the provider is not carrying price risk while it waits for your deposit, floating offers normally have the tightest spread.
How a fixed rate works
With a fixed rate, the provider guarantees the amount you will receive, provided you send the exact deposit amount within the time limit (typically 10 to 30 minutes). The provider hedges the price risk, and the cost of that hedge is built into a slightly wider spread.
If your deposit arrives late or in a different amount, the provider will usually either re-quote at the current rate or refund you, depending on its policy.
Side by side
| Floating rate | Fixed rate | |
|---|---|---|
| Amount you receive | Estimated; set when the deposit confirms | Guaranteed if you send the exact amount in time |
| Typical spread | Lower | Slightly higher |
| Risk of slippage | Yes, in both directions | None inside the time window |
| Time limit | Generous | Strict (often 10-30 minutes) |
| Best for | Fast networks, liquid pairs, calm markets | Exact payments, slow networks, volatile markets |
A simple rule
If the coin you send confirms in under a couple of minutes (Solana, Tron, XRP, most layer-2 networks) and you do not need an exact figure, take the floating rate: there is little time for the price to move, and you keep the tighter spread.
If you send Bitcoin or Monero during a volatile hour, or you are paying an invoice that must arrive in full, pay the small premium for a fixed rate.
AltoSwap lists both types for every provider that offers them, ranked together by the amount you receive, so you can see exactly what certainty costs on your pair right now.
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