Info
A P2WPKH enter weighs 68 vB (assuming the worst-case with a high-r signature, -0.25 vB with a low-r signature) and a P2WPKH output weighs 31 vB for a complete of 99 vB.
A P2TR enter weighs 57.5 vB and the output weighs 43 vB for a complete of 100.5 vB.
P2WPKH is cheaper if you pay your self as typically as you spend inputs
P2TR is about 1.5% dearer throughout the lifecycle! Does that imply that I ought to proceed utilizing P2WPKH?
Sure, if virtually all your transactions have a single enter and create change, you might certainly save a tiny portion of charges by utilizing P2WPKH.
The under desk exhibits the whole weight of transactions beneath the belief that almost all of them are single-input and creating change, created utilizing both P2TR or P2WPKH outputs, and certainly one of X transactions having a two inputs as an alternative of 1:
If just one out of seven transactions makes use of two inputs and also you all the time create change, you’ll be capable to save as much as 1.5% by sticking to P2WPKH.
If 1 out of 6 transactions has no less than two inputs or in case you can generally keep away from creating change, your complete transaction weight would find yourself being decrease in case you use P2TR.
More often than not, others are paying you, and often the sender pays for the output (otherwise you pay a flat charge to withdraw no matter output sort). Each time others pay you, you solely pay for the enter. P2TR inputs are 15% cheaper than P2WPKH inputs (57.5 vB vs 68 vB). Sure, which means externalizing the associated fee on the sender, however the senders don’t get a say in how the recipient desires to receives a commission, and senders usually appear wonderful with paying for a P2WSH output (which prices the identical as P2TR).
Batching
Everytime you use extra inputs than you ship outputs to your self (e.g. if you make huge transactions for batching funds, consolidation transactions, the funds you obtain are smaller than those you make), otherwise you’re capable of keep away from change altogether, it will likely be cheaper to make use of P2TR:
Person situations
Hardly any pockets operator’s spending sample would ever match the belief that almost all transactions have just one enter and create change. Let’s think about a number of consumer situations.
Hodler
In case you frequently DCA, you’ll have many small-value UTXOs. It’s possible you’ll sometimes sweep them into chilly storage, or in any other case consolidate some. Then, or each time else that you just do create a transaction, it can doubtless have a number of inputs. In case you purchase greater quantities without delay, you should still maintain your UTXOs for an unknown period of time, and it’s not possible to know now what the feerates will likely be like if you really wish to spend the UTXOs. In case you time your UTXO administration transactions to low feerates, you’ll most likely create most of your self-sent outputs at decrease feerates than the eventual spend. In both case, you’ll create fewer change outputs than inputs, and it advantages you to have lighter inputs everytime you do resolve to spend.
Pay as typically as you obtain
It’s not clear who would have such a spending sample, however let’s say you obtain funds precisely as typically as you make them and each fee creates change. In that case, solely about half of the UTXOs you obtain had been despatched to you by your self. Clearly, within the long-term you’ll spend about twice as many inputs as you create change outputs. It’s going to due to this fact be cheaper to make use of P2TR.
Client in a round Bitcoin financial system
An exception is likely to be a consumer that lives within the Bitcoin round financial system. You get your wage in bitcoin a few times a month and peel all of your funds off from that over the remainder of the time (let’s ignore the privateness implications for a second). On this case, you would possibly create change 6× as typically because the variety of occasions that you’ve a second enter. Assuming this sample, you’d be capable to save as much as 1.5% by utilizing P2WPKH as an alternative of P2TR.
Service provider/Service
In case you provide a service or are a service provider, you’ll obtain many smallish funds or deposits, and infrequently will make bigger funds to cowl prices or pay suppliers. Everytime you receives a commission, your prospects pays to your recipient output, however you solely pay for the inputs. While you make your bigger funds, you’re more likely to have two or extra inputs. P2TR inputs are 15% cheaper than P2WPKH inputs (57.5 vB vs 68 vB). It’s possible you’ll sometimes consolidate many low-value UTXOs at opportune mempool situations. Typically, your depend of inputs will closely outweigh your depend of change outputs. It follows that it’s cheaper so that you can use P2TR.
Alternate/Brokerage
In case you give out P2TR deposit addresses, your prospects pay for the bigger outputs, and you’ve got much less price if you spend these deposits. Most exchanges and brokerages batch withdrawals. Batched fee transactions will typically have a number of inputs, however solely require a single change output to facilitate many withdrawals. While you consolidate leftover small inputs, you accomplish that at opportune moments with low feerates, and the various smaller inputs simply outweigh the creation of 1 heavier output in your consolidation transaction. While you do need to make a transaction at a excessive feerate sometimes, it serves you properly that your inputs are cheaper. P2TR is unquestionably cheaper for you than P2WPKH.
Multi-wallet setup with spend-only pockets
One other exception can be, in case you facilitate a high-volume of funds per a multi-wallet setup that features a “spend-only pockets”. You’d sometimes high up that pockets with massive UTXOs from which you peel off funds. In that case, I might see the way you would possibly really find yourself with creating change 6× as typically because the variety of occasions that you’ve a second enter. In that case, you’d be capable to save as much as 1.5% by utilizing P2WPKH as an alternative of P2TR for the spend-only pockets. In case you have a very huge operation, that may use each P2WPKH and P2TR, you might probably save a bit extra by preferring P2TR inputs and P2WPKH change outputs at excessive feerates, whereas preferring P2WPKH inputs and P2TR change outputs at low feerates. In case you do find yourself having extra inputs than change outputs, you must have picked P2TR within the first place.
Conclusion: P2TR is cheaper in virtually each situation
Whereas it’s affordable to attend with switching whereas particularly exchanges are nonetheless dragging their ft to allow assist for sending to P2TR outputs, simply from a price perspective, P2TR finally ends up being cheaper in virtually each situation. Moreover, if it is advisable to create transactions at excessive feerates sometimes, the lower-weight inputs will save price. Total, you’d save as much as 15.4% in transaction charges by utilizing P2TR as an alternative of P2WPKH. In case you make vastly extra small funds than you obtain funds, you could save as much as 1.5% by sticking to P2WPKH.
