The arrival time shown next to a pending deposit is the site’s confirmation count for that coin multiplied by the chain’s average block time, plus an allowance for how long the transaction will wait in the queue at the fee you paid, and it is recalculated every time a block arrives. It is an estimate rather than a promise, and the way it is built explains why it is accurate on fast chains and loose on Bitcoin.
Four parts go into the figure at most roulette games with crypto cashiers.
- The confirmation count – Fixed per coin by the site, and the same for every deposit below the large-amount threshold. This is the number the display counts down from.
- The average block time – Ten minutes for Bitcoin, two and a half for Litecoin, twelve seconds for Ethereum, three for Tron. The site uses the long-run average, not the time the last block happened to take.
- The queue wait – For chains where fees decide position, the site compares the fee rate your transaction paid with the current rate for next-block inclusion. If yours is above it, the queue wait is one block. If below, the site estimates how many blocks will pass before the rate falls to yours, and adds that. This is the part that changes most between deposits.
- The live adjustment – Once the transaction is in a block, the queue wait drops to zero, and the display shows the remaining confirmation times block time. Each new block reduces it by one step. If a block takes longer than average, the display stalls rather than counting down, which is why a bitcoin estimate can read “about 10 minutes” for twenty.
Examples of the display for four coins, each for a deposit sent at a normal fee:
- Bitcoin, three confirmations – Sent, shows “about 35 minutes”, made of one block of queue wait plus three blocks at ten minutes. After the first block, “2 of 3 confirmations, about 20 minutes”. The range is wide because each block can take two minutes or twenty.
- Litecoin, three confirmations – Shows “about 8 minutes”. Blocks are regular enough that the display is usually within a minute or two of the actual credit time.
- Ethereum, twelve confirmations – Shows “about 3 minutes” on a normal day. Because blocks arrive every twelve seconds without variation, the countdown is close to exact. If the gas price paid was below the base fee, the display shows “waiting for inclusion” with no time, since the transaction cannot be mined at all until the base fee falls.
- Tron, twenty confirmations – Shows “about 1 minute” and is rarely off by more than a few seconds.
The estimate is wrong in three situations, and the display usually says so:
- Fee below the current rate – The queue wait cannot be predicted, and better sites show “may be delayed” or “fee too low” rather than a time. This is the case for a replace-by-fee bump.
- Chain slower than average – A run of slow blocks on Bitcoin can double the figure. The display stalls at the same estimate until the next block.
- Network incident – A reorganisation or a halt resets or freezes the count. The display may drop a confirmation that it had already shown.
Read the figure as a floor on fast chains and a midpoint on Bitcoin. Where the page shows no time at all, the fee is the problem, and the deposit will not move until it is raised or the chain quietens.
