Getting a grip on mempool.space

I'm trying to get my head around transaction fees. I've seen a lot of mentions of mempool.space as a way to figure out how much to pay for speedy BTC transfers. Right now on mempool.space Check out this image: High Priority is showing 3 sat/vB, medium priority also at 3 sat/vB, and low priority at 1 sat/vB. So, just to clarify, 1 satoshi is 0.00000001 Bitcoin, right? That puts it at roughly USD0.001074296 per vB. And for 3 satoshi, that comes to 0.00000003 Bitcoin, so about USD0.003222888 per vB. Looking at the image again, on the far right box, it shows ~2 sat/vb 1-40 sat/vb 0.02 BTC 1661 transactions in around 9 minutes. So, 0.02 BTC translates to 0.02000000 Bitcoin, which equals $2148.59 (with the current BTC price at USD107,429.60)? That feels like a steep fee, doesn't it? Am I getting this all wrong? What's the best rate to use for my transactions? Thanks!

Right. The 0.02 BTC displayed there is not the transaction fee for a single transaction. Mempool.space estimate that if a miner (or a mining pool) find a block now, they will collect 0.02 BTC as transaction fee. Take note that miners prioritize transactions based on their fee rate (at sat/vbyte) and that's what you should set whenever you want to make a transaction.

This depends on the seize of your transactions, but for simple transaction just follow recommended transaction fees. Currently this is 2 sat/vB but even 1 sat/vB should probably be confirmed quickly. For more complex transactions including multiple inputs and outputs that could be different. Here is one website that can calculate fees for specific number of inputs/outputs: https://coinb.in/#fees

I like to say: "it depends". Are you in a rush, or do you want to pay as little as possible? You should probably read my topic on consolidating inputs. When I determine the fee for a fast confirmation based on mempool.space, I hover my mouse above the Mempool Goggles on the left. At the moment, many big squares pay 1.00 sat/vbyte. That means, if you pay 1.1 or even 1.01 sat/vbyte, your transaction will be prioritized before them. Since 1.01 is still very close the minimum (which is 1.00 sat/vbyte), this is a good fee for any transaction. Note that your milage may vary: if the next Bitcoin block takes a long time, other Bitcoin transactions will compete for the block space, and your transaction will move further down the line. If you're not in a hurry, that's not a problem. If you are in a hurry and still want to pay as little as possible, you can increase your transaction fee using RBF (Replace By Fee) later if it takes too long to confirm.

The fee rate recommendation is below text "Transaction Fees". As for which recommendation, you can hover your cursor (on desktop) or touch (on mobile) the priority text to see their defnition of high, medium, low and no priority. As stated by @LoyceV, it should be depends on OP needs since mempool.space shows fee rate recommendation. Some wallet also have preview feature where you can see transaction size before the TX is signed/broadcasted.

Looking at OP's post history, it seems like he used Bitcoin Core in the past and mistakenly sent a transaction with a very low fee, and can't do RBF on it. Do you still use Bitcoin Core OP? I use Electrum, and their recommendation usually does not differ that much mempool.space or other block explorers. It usually hovers around medium-high priority on the mempool.space. Btw, I also can't access the image you posted, not sure if the hosting has already deleted it or something else happened. CMIIW.

In the past days we had regularly non-full blocks, so even reasonably sized transactions with 1.00 sat/vB (lowest by default relayable fee rate) would or have been mined into blocks. Sadly OP doesn't seem to care to respond or give an update. For chosing an "optimal" fee rate depending on my own confirmation urgency, I click on the first pending block candidate on mempool.space to see how fee rates are distributed over percentage of weight. Depending on the age of candidate block and how fee rates are distributed, I try to figure out what could be an optimal fee rate to get a transaction confirmed in the next block or in some later time frames. It might be necessary to also look at second pending block candidate or further down the pending block candidate queue to figure out what fits, especially when the pending block queue is longer than mempool.space offers to inspect individual candidate blocks. A good assessment is highly depending on current mempool situation and transaction pressure. It's not rocket science but it's also not so easy to give newbies or less experienced users a fool-proof recipe for any situation. Questions about good or optimal fee rates have been asked gazillion of times, so there are plenty of threads to find in the past.

Thank you all for the explanation. Much appreciated. Yes, that transaction finally went through after 8 or 9 months (if I'm not mistaken). And yes, I'm still planning to use Bitcoin Core. Edit: Reason being I know it has been there and hopefully will be there so my wallet is recoverable. What's the history like with Electrum? Is Electrum better transferring out from exchanges for offline safe-keeping? Easier to use? Not sure what happened to the image. Any ideas how this forum post pic or more accurately, where do we post pics to reference something in this forum?

You don't have to use bitcoin core, so that you will be able to recover your wallet. If you have the private key, you will be able to recover your wallet at any time. Electrum is a SPV wallet and you don't have to download the blockchain for using that. That's the main advantage of electrum over bitcoin core. Electrum can be also used offline and that's surely a good option for cold storage.

Make a backup of your wallet.dat file via "File->Backup Wallet" and keep the backup's drive in a safe if you haven't done that already, that'll make sure that it'll be recoverable. BTW, if you're still using an old version and decided to update in the future, your wallet may encounter compatibility issues. It'll be documented so it'll not be much of an issue if you can follow instructions. Not essentially better, each has its own advantages, but it has additional features like "freezing addresses/UTXO", other fee rate estimation options like ETA (same as Core), mempool (requires timing and basic bitcoin knowledge) and Static; and other common wallet features. If you don't specifically need any of its features, stick to what you have. Your image BBCODE is fine (checked it via quote), It's just the forum doesn't allow newbies from displaying images until they reach jr member rank. Also, some image hosting sites aren't supported like imgur; your best option is talkimg (ANN Thread) which is the commonly used image hosting site here.