A fixed rate locks the amount you will receive at the moment you create the swap. A floating rate gives you the market rate at the moment your deposit confirms and the swap executes, so the final amount can land slightly above or below the estimate you saw.
Some swap services offer both and let you pick. The SwapRocket exchange uses a floating rate only. This guide explains how both models work, what each one costs you, and how to keep a floating-rate swap close to its estimate.
- Fixed rate: the quote is held for a set window. You pay for that certainty with a wider margin built into the quote.
- Floating rate: the swap executes at the market rate when your deposit confirms. The margin is usually tighter, and you carry the price movement during confirmation.
- On SwapRocket: floating rate only. The estimate shown before you send already includes the fee and the payout network fee, and nothing is added afterwards.
- What moves the result: how volatile the pair is and how long the deposit takes to confirm.
How a fixed-rate swap works
With a fixed rate, the service commits to a quote for a short window, usually long enough for your deposit to arrive and confirm. If the deposit arrives inside that window and matches the amount you entered, you receive exactly what was quoted.
The service takes on the price risk for that window, and it charges for it. A fixed quote is normally a little worse than the floating estimate for the same pair at the same moment. The terms also matter: if your deposit arrives late, or the amount differs from what you entered, a fixed-rate swap can be re-quoted or refunded. Read the conditions shown on the screen before relying on one.
SwapRocket does not offer fixed-rate swaps. If you need a locked amount, that is a feature to look for elsewhere.
How a floating-rate swap works
With a floating rate, the number you see before sending is an estimate. The swap executes at the market rate once your deposit has the confirmations it needs. If the market moves in your favour during that time you receive a little more than the estimate, and if it moves against you, a little less.
There is no cushion priced in for holding the rate, which is why the starting estimate on a floating swap tends to be tighter than a fixed quote.
Fixed vs floating at a glance
| Fixed rate | Floating rate | |
|---|---|---|
| What you see before sending | A locked amount | An estimate |
| What you receive | The quoted amount, if you meet the terms | The market rate at execution |
| Who carries price movement | The service, and it prices that in | You |
| Typical cost | Wider margin | Tighter margin |
| Suits | Volatile pairs, slow deposit chains, exact amounts | Liquid pairs, stablecoins, quick confirmations |
| Offered on SwapRocket | No | Yes |
What changes the amount you receive
Three things decide how far the final amount sits from the price you had in mind.
Spread
Every swap is priced with a spread, the gap between the market mid-price and the rate you are offered. It is narrow on heavily traded pairs and wider on thin ones. A service advertising "no fee" still earns from the spread, which is covered in how "free" crypto swaps make their money.
Price movement during confirmation
This is the part that separates the two models. Between creating the swap and execution, the market keeps moving. A fixed rate absorbs that movement and a floating rate passes it on. The effect is small on a calm day and noticeable when a coin is moving fast. The mechanics are explained in crypto slippage and how to cut it.
Confirmation time
A swap starts when your deposit is confirmed on its own chain, not when you press send. A Bitcoin deposit sent with a low network fee during a busy period can sit unconfirmed for a long time, and the longer the wait, the more room the rate has to drift. Typical times per chain are listed in how long crypto swaps take.
When a fixed rate is worth paying for
A fixed rate earns its extra margin when:
- The pair is volatile, or one side is a thinly traded coin.
- The deposit chain is slow or congested, so execution is a while away.
- You need an exact output, for example to pay an invoice in USDT.
- The amount is large enough that a small percentage is real money. As an example, a 1% move on a 10,000 USDT swap is 100 USDT, while on a 100 USDT swap it is 1 USDT.
It is poor value when you are swapping between stablecoins, or between liquid coins on a quiet day with fast confirmations. In those cases you pay for protection against a move that rarely happens.
When a floating rate is the better deal
A floating rate usually gives the better result when:
- Both coins are liquid, such as BTC, ETH and the major stablecoins.
- The market is quiet.
- Your deposit will confirm quickly.
- A small difference from the estimate does not matter to you.
It can disappoint when the coin is in the middle of a sharp move, the pair is illiquid, the deposit chain is congested, or major news lands while you wait.
What SwapRocket uses: a floating rate only
SwapRocket is a crypto-to-crypto exchange with a single rate type.
- Floating rate. The estimate is shown before you send. It already includes the fee and the payout network fee, and nothing is added afterwards. The final amount follows the market at execution.
- One licensed liquidity provider executes each swap.
- Non-custodial. You send from your own wallet and the swapped coins go to the address you enter. There is no account and no email.
- No KYC for standard swaps. The liquidity provider screens transactions and can, rarely, hold a flagged one and ask for verification.
- Timing. A typical swap takes 5 to 30 minutes, set mostly by how fast the deposited coin confirms.
- Availability. The service is not offered to residents of the United States or the United Kingdom.
The steps are on the how it works page, and your first crypto swap walks through one from start to finish.
How to keep a floating-rate swap close to the estimate
- Send straight away. The estimate is live. If you create a swap and send an hour later, the market has had an hour to move.
- Pay a sensible network fee on the deposit. A deposit that confirms in the next block or two leaves little time for drift. If a Bitcoin deposit is stuck, RBF and transaction acceleration explains how to speed it up.
- Avoid the worst moments. Scheduled economic announcements, exchange incidents and liquidation cascades are when estimates go stale fastest. If nothing is urgent, wait for the market to settle.
- Check the estimate first. A converter page such as BTC to USDT or SOL to USDT shows the current rate before you start.
- Match the network. USDT and USDC exist on several chains. Pick the same network in the swap form that your wallet will send on and receive on. The differences are covered in the USDT networks guide.
Three common situations
ETH to USDT before a quiet weekend. Both sides are liquid and Ethereum confirms in minutes, so a floating rate on the ETH to USDT exchange page normally lands close to the estimate. If you need an exact USDT figure, send slightly more ETH than the bare minimum so a small move does not leave you short.
BTC to XMR. Bitcoin is the slower leg here. Set a network fee that gets the deposit into an early block, then start from the BTC to XMR exchange page. The gap between estimate and result is mostly the price change over those confirmations.
SOL to ETH during a sharp move. Solana confirms quickly, which helps, but both coins can move a lot in a short time. On the SOL to ETH exchange page, expect the result to differ from the estimate more than usual, or wait until the market calms down.
FAQ
Does SwapRocket offer fixed-rate swaps?
No. SwapRocket uses a floating rate only. The estimate you see before sending includes the fee and the payout network fee, and the final amount depends on the market rate when the swap executes.
Is a floating rate cheaper than a fixed rate?
On a calm market it usually is, because a fixed quote carries extra margin to cover the service's price risk. On a volatile day a fixed quote can leave you better off, since it shields you from a move against you. Neither is cheaper in every case.
Why did I receive less than the estimate?
On a floating-rate swap the estimate is not a promise. The market moved between the moment you saw it and the moment your deposit confirmed and the swap executed. Slow confirmations and volatile pairs make the gap larger.
Can I receive more than the estimate?
Yes. A floating rate works in both directions. If the market moves in your favour before execution, the payout is higher than the estimate.
Is a fixed rate always guaranteed?
Only within the terms of the service offering it. Fixed quotes normally expire after a set window and assume you send the exact amount you entered. A late or mismatched deposit can be re-quoted or refunded.
Related reading
- Crypto swap fees and the costs you do not see
- Crypto slippage explained
- How no-KYC crypto exchanges work
Start a swap
Pick your pair on the SwapRocket exchange, check the floating-rate estimate, and send from your own wallet. Answers to common questions about rates and timing are in the FAQ.
