---
title: Floating rate: estimate vs payout, what changes
description: The estimate is a snapshot; the payout is set when your deposit confirms. A worked example of what moves the number and how to plan an amount that must arrive.
url: https://sablebolt.io/blog/floating-rate-estimate-vs-payout
---

[How swaps work](https://sablebolt.io/blog)

# Floating rate: what changes between the estimate and the payout

Sablebolt Team 18 October 2026 7 min read

Contents

1. Three moments, three numbers
2. A worked example, start to finish
3. What moves the number
4. Why slow chains drift more than fast ones
5. The same example from the Bitcoin side
6. Fixed-rate swaps are not offered
7. How to plan an amount that must arrive
8. Checklist before you send
9. FAQ

You type 500 USDT into the form and it says you will get about 0.00495 BTC. Forty minutes later the status page says 0.00491 BTC delivered. Nothing went wrong. The rate on sablebolt.io is floating, and this guide explains exactly what that means: which number is fixed when, what moves it, and how to send so that the amount you need actually arrives.

The numbers below are made up to keep the arithmetic easy to follow. The form shows the real ones.

## Three moments, three numbers

A floating-rate swap has three moments that matter. Only the last one sets the payout.

| Moment | What you see | Is it final? |
|---|---|---|
| You enter an amount | "You get (estimate)" — refreshes every 60 seconds while the form is open | No. It is a snapshot of the market at that second. |
| You send the deposit | The status page repeats the estimate from the moment you created the swap | No. Your transaction is still waiting for confirmations. |
| The deposit confirms | The rate is set; the payout is calculated from it | Yes. This is the number that gets sent. |

The rule in one sentence: **the final amount is set when your deposit confirms, not when you looked at the form.** Everything in between is time during which the market can move. How much time depends on the chain you send from, and that is the whole story of drift.

## A worked example, start to finish

Suppose you swap [USDT TRC-20 to BTC](https://sablebolt.io/swap/usdt-trc20/btc) and the market is at 1 BTC = 100,000 USDT when you open the form. Say the payout network fee shown is 0.00005 BTC.

**Step 1 — the estimate.** 500 USDT ÷ 100,000 = 0.005 BTC before the fee. The form subtracts the Bitcoin network fee for the payout, so "You get" shows 0.005 − 0.00005 = **0.00495 BTC** . What that line includes, and what it does not, is set out on the [fees page](https://sablebolt.io/fees) .

**Step 2 — you send.** You copy the one-time deposit address, send 500 USDT from your TRON wallet, and the status page moves to "Confirming". USDT on TRON needs 1 confirmation, which takes about 2–5 minutes.

**Step 3 — the deposit confirms.** In those four minutes BTC moved. Two cases:

| Market during confirmation | Rate when the deposit confirms | 500 USDT at that rate | Minus the network fee | Delivered |
|---|---|---|---|---|
| BTC rose 0.4 % | 100,400 | 0.0049801 BTC | 0.00005 BTC | 0.0049301 BTC |
| BTC fell 0.4 % | 99,600 | 0.0050201 BTC | 0.00005 BTC | 0.0049701 BTC |

In the first case you receive 0.0000199 BTC less than the estimate. In the second you receive 0.0000201 BTC more, and the status page shows the difference next to the delivered amount. Both are normal outcomes of the same mechanism: the rate was read at confirmation, not at the quote.

≈ 2–5 min 1 confirmation on TRON

[Swap USDT TRC-20 to BTC](https://sablebolt.io/swap/usdt-trc20/btc)

## What moves the number

Two things, and only two.

**1. The market during confirmation time.** The pair's price at the moment of confirmation is what counts. For a stablecoin-to-stablecoin route such as [USDT TRC-20 → USDT BEP-20](https://sablebolt.io/swap/usdt-trc20/usdt-bep20) this is small, because both sides track the same dollar. For a route with BTC, ETH or XMR on either side it is the market's move over the confirmation window.

**2. The network fee of the payout.** The fee is quoted for the receiving network and comes out of the payout. On Bitcoin and Ethereum the fee level changes with congestion; if the network is busier at payout time than at quote time, the deduction is larger. On TRON, BNB Smart Chain and Solana the fee is small and steady, so this term barely moves.

Nothing else is added for the time the swap took: the components of the price are the ones listed on the [fees page](https://sablebolt.io/fees) , read at confirmation.

## Why slow chains drift more than fast ones

Drift is the market move over the confirmation window. A longer window gives the market more time to move, in either direction. The windows on sablebolt.io, by the chain you send from:

| You send on | Confirmations before the swap starts | Typical window |
|---|---|---|
| TRON (USDT TRC-20, TRX) | 1 | ≈ 2–5 min |
| BNB Smart Chain | 10 | ≈ 2–5 min |
| Solana | 1 | ≈ 2–5 min |
| XRP Ledger | 2 | ≈ 2–5 min |
| TON | 20 | ≈ 3–7 min |
| Ethereum (ETH, USDT ERC-20, USDC) | 15 | ≈ 4–10 min |
| Dogecoin | 3 | ≈ 4–10 min |
| Zcash | 6 | ≈ 9–19 min |
| Monero | 5 | ≈ 11–24 min |
| Litecoin | 5 | ≈ 14–29 min |
| Bitcoin | 2 | ≈ 21–44 min |

Compare the two ends. From TRON the window is a few minutes; the rate at confirmation is close to the rate you saw. From Bitcoin the window is 21–44 minutes, and a half-hour move in BTC is routinely larger than a four-minute move. That is why a [BTC → USDT TRC-20](https://sablebolt.io/swap/btc/usdt-trc20) swap sees more difference between the estimate and the payout than the same amount going the other way.

The direction of the move is not predictable. Over many swaps the differences cancel out; over one swap you simply get the rate of that moment.

## The same example from the Bitcoin side

Now reverse it: [BTC → USDT TRC-20](https://sablebolt.io/swap/btc/usdt-trc20) , 0.01 BTC, same imaginary market of 100,000.

- Estimate: 0.01 × 100,000 = 1,000 USDT, minus the TRON payout fee — say 1 USDT in this example — gives **999 USDT**.
- You send 0.01 BTC. Two Bitcoin confirmations take 21–44 minutes.
- During those minutes BTC moves 1.5 %, which is not unusual over half an hour:

| Market during confirmation | Rate at confirmation | 0.01 BTC at that rate | Minus fee | Delivered |
|---|---|---|---|---|
| BTC fell 1.5 % | 98,500 | 985 USDT | 1 USDT | 984 USDT |
| BTC rose 1.5 % | 101,500 | 1,015 USDT | 1 USDT | 1,014 USDT |

A 15-USDT swing on a 1,000-USDT swap. The TRON-side example above swung by about 0.4 % because the window was ten times shorter. Same mechanism, different window.

## Fixed-rate swaps are not offered

Some services offer to lock a rate for a few minutes. Sablebolt does not offer that at the moment, and the site says so on the [how it works](https://sablebolt.io/how-it-works) page rather than hiding it. Every swap here is floating: the estimate is honest about being an estimate, and the payout is calculated from the market at confirmation.

If you need a guaranteed figure on the receiving side, the next section is how to get close to one without a fixed rate.

## How to plan an amount that must arrive

The receiver needs at least a certain amount — an invoice, a minimum deposit, a debt. The method is to oversend by a margin that covers the window.

1. **Decide the floor.** The amount that must arrive, call it F. Say F = 300 USDT.
2. **Pick a margin for the window.** From a fast chain a small margin is enough; from Bitcoin or Monero use a larger one. You choose the figure; the table above tells you how long the window is. For this example: 1 % from TRON, 3 % from Bitcoin.
3. **Set the target.** T = F × (1 + margin). From TRON: 300 × 1.01 = 303 USDT. From Bitcoin: 300 × 1.03 = 309 USDT.
4. **Raise "You send" until "You get" shows at least T.** The network fee is already inside "You get", so you do not add it separately.
5. **Send promptly.** The estimate refreshes every 60 seconds. Creating the swap and then sending an hour later means the window is an hour, not four minutes.
6. **Send the exact amount shown.** The plan only works for the amount the estimate was made for; a smaller deposit cannot produce the planned payout.

If the market moves your way, the receiver gets a little more than F and the status page shows the surplus. If it moves against you within the margin, they still get at least F. If it moves by more than the margin — rare in a four-minute window, possible in a forty-minute one — they get slightly less, and you top up.

## Checklist before you send

- You read "You get" within the last minute, not ten minutes ago.
- You know the window for your sending chain (table above) and sized the margin for it.
- The amount that must arrive is below "You get" by at least your margin.
- The deposit is going out now, in one transaction, for exactly the amount shown.
- You have the status link saved, so you can compare the delivered amount with the estimate.

## FAQ

Why did I get less than the estimate?

The market moved against the pair between your quote and the confirmation of your deposit, or the payout network's fee rose in that time. The status page shows the delivered amount; the estimate was a snapshot.

Why did I get more than the estimate?

Same reason, other direction. When the payout is larger than the estimate, the status page shows the difference next to the delivered amount.

Does the 60-second refresh lock anything?

No. It keeps the number on the screen current while you are deciding. The rate is set when the deposit confirms, whether that is 3 minutes or 40 minutes after you clicked.

Can I get a fixed rate?

Not on sablebolt.io at the moment. The site describes the floating rate plainly and does not sell a lock. Plan with a margin instead.

Is there a hidden fee in the difference?

No. The difference between estimate and payout is the market movement over the confirmation window plus any change in the payout network fee. The [fees page](https://sablebolt.io/fees) lists what the estimate is made of.

Which routes drift the least?

Stablecoin-to-stablecoin routes from a fast chain: both sides track the dollar and the window is a few minutes. The ones that drift most are routes from Bitcoin, Litecoin or Monero into anything volatile.

## Related posts

- [How swaps work Reading a swap status page: every state from waiting to finished Waiting, Confirming, Swapping, Sending, Done — what each stage means, which hash to look up where, and when a wait is normal. 19 October 2026 9 min](https://sablebolt.io/blog/reading-a-swap-status-page)
- [Monero & Zcash BTC to XMR step by step: confirmations, timing and the 10-block lock Two Bitcoin confirmations, the swap, then ten Monero blocks before you can spend. The whole timeline, with the address formats and explorer checks. 21 October 2026 8 min](https://sablebolt.io/blog/btc-to-xmr-step-by-step)
- [USDT between networks How to pay someone whose USDT wallet is on a different network Their address starts with 0x and your USDT is on TRON. Three ways to make the payment, and what the receiver will see. 14 October 2026 9 min](https://sablebolt.io/blog/pay-usdt-to-a-different-network)