On memepool.space on the top you will see a search box. Enter the transaction hash and it will give you an approximate time when you transaction will get confirmed. The same can be don on blockhair.com

If it is high priority then generally the first confirmation happens in 10 minutes. If it is medium priority then generally the first confirmation happen between 20 to 40 minutes.

Possibly a day or two, possibly never. There is a reason why priority is used instead of the actual estimated time.

No estimation will ever be accurate because there are a lot of variables in play here. For example, if the number of transactions increases after you send a transaction, then your transaction would take longer. Miners can also choose the transactions to include into their block.

You can use this site https://jochen-hoenicke.de/queue/#BTC,2h,weight



Currently the weight on 10+ sat/vbytes is 43.403 vMB since the average weight of each Bitcoin block is 2 MB and it takes 10 minutes to mine one block, so it may takes around 6-7 hours CMIIW.

Some other mempool observer websites.
https://mempool.jhoenicke.de/#BTC,24h,weight
https://mempool.space/
https://mempool.space/graphs/mempool

Estimate waiting time for a transaction to be confirmed is not 100% correct because mempools are dynamic and Bitcoin users can broadcast more new transactions to mempools and affect your estimation.

You can paste your transaction hash here and see Priority of the transaction.
https://blockchair.com/bitcoin

If you want a quick confirmation, wait until the time from the last block is +15 minutes and see what the Next Block will look like. Through that and evaluating the fees above, you can find out the appropriate fees for inclusion in the next block, and the average will definitely be less than 10 minutes.
Fees are estimated according to an analysis of the data of the current block and the next block, the congestion of current transactions, but no one can predict the shape of the upcoming transactions, so these estimates, even if they are based on real-time data, are a look at the mempool in the past.

To make it easy on you and have the higher possibility of getting your transaction confirmed on time, try to check through the mempool and use the highest priority, this means you're more likely to get your transaction confirmed within the next block confirmation, when you pay a lower transaction fee under the low priority, then the transaction ID on the search engine will indicate the estimation on time left for the confirmation of your transaction.

That is assuming the mempool size doesn't grow at all, hence no new transactions. That is not a realistic assumption and it's likely going to take several days instead.

Because mempools can change quickly, Bitcoin users must use opt-in Replace By Fee RBF for their transactions. If they don't use RBF for initial transaction, they will have to use Child Pay For Parents CPFP later, and it is less convenient than RBF and more expensive than RBF in total transaction fee.

Not all mempools accept full-RBF as it is an alternative for RBF.

Replace by Fee.

Don’t use the no priority price. Those are so low that it might take forever to confirm. Just look at a few previous blocks and a few blocks coming up and use that fee in there. Maybe at 1-2 sat/vbyte to come up first in line.

Sure this can change and might take longer to confirm but it’s pretty accurate. Just remember to enable RPF and you can always increase the fee. Also keep in mind the 10 mins is an average time for blocks, it can be as low as a few seconds or as high as an hour.

As explained above, this depends on many variables, and we can only estimate probabilistically. If you send a very high fee, it will most likely be confirmed in the next block, and we know that on average that will happen in 10 minutes. But I have sent a transaction with the highest fee to be confirmed quickly, the next block took 1 hour to be confirmed, my transaction got stuck in the mempool, and in the end I had to do rbf so that it could be confirmed. I have also sent a transaction at a medium rate because I was not in a hurry for it to be confirmed, and after 20 minutes I look at it and it has already been confirmed because 5 or 6 blocks have been mined in that time interval. One thing is the estimate you make and another what happens after you send the transaction, such as if there is a huge dump of transactions or if the next block (or blocks) takes a long or short time to be confirmed.