Details
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 101.5 vB.
P2WPKH is cheaper if you pay your self as usually as you spend inputs
P2TR is about 1.5% costlier throughout the lifecycle! Does that imply that I ought to proceed utilizing P2WPKH?
Sure, if nearly your entire transactions have a single enter and create change, you may certainly save a tiny portion of charges through the use of P2WPKH.
The under desk exhibits the overall weight of transactions underneath the belief that almost all of them are single-input and creating change, created utilizing both P2TR or P2WPKH outputs, and one in all X transactions having a two inputs as a substitute of 1:
If just one out of seven transactions makes use of two inputs and also you at all times create change, you’ll be capable of save as much as 1.5% by sticking to P2WPKH.
If 1 out of 6 transactions has at the least two inputs or should you can typically keep away from creating change, your complete transaction weight would find yourself being decrease should you use P2TR.
More often than not, different customers are paying you, and often the sender pays for the output (otherwise you pay a flat price 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, that externalizes the price to the sender, however the senders don’t get a say in how the recipient desires to receives a commission, they usually typically already are good to pay to P2WSH (which prices the identical as P2TR).
Batching
Everytime you use extra inputs than you ship outputs to your self (e.g. if you make massive transactions for batching funds, consolidation transactions, the funds you obtain are smaller than those you make), otherwise you’re in a position to keep away from change altogether, it is going to be cheaper to make use of P2TR:
Consumer eventualities
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 contemplate a couple of person eventualities.
Service provider/Service
If you happen to provide a service or are a service provider, you’ll obtain many smallish funds or deposits, and sometimes 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. Once you make your bigger funds, you’re prone 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. Usually, your rely of inputs will closely outweigh your rely of change outputs. It follows that it’s cheaper so that you can use P2TR.
Hodler
If you happen to repeatedly DCA, you should have many small-value UTXOs. It’s possible you’ll sometimes sweep them into chilly storage. Then, or each time else that you simply do create a transaction, it is going to doubtless have a number of inputs. If you happen to purchase larger quantities without delay, you should still maintain your UTXOs for an unknown period of time, and it’s unattainable to foretell what the feerates shall be like if you really wish to spend the UTXOs. If you happen to 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 few change outputs, and it advantages you to have lighter inputs everytime you do determine to spend.
Pay as usually as you obtain
It’s not clear who would have such a spending sample, however let’s say you obtain funds as usually as you make them and each fee creates change. In that case, solely about half of the UTXOs you obtain have been despatched to you by your self. Clearly, within the long-term it’s important to spend about twice as many inputs as you create change outputs. It should due to this fact be cheaper to make use of P2TR.
Multi-wallet setup with spend-only pockets
One exception could be, should 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 giant UTXOs from which you peel off funds. In that case, I may see the way you would possibly really find yourself with creating change 6× as usually because the variety of occasions that you’ve got a second enter. In that case, you’d be capable of save as much as 1.5% through the use of P2WPKH as a substitute of P2TR for the spend-only pockets. If you happen to do find yourself utilizing extra inputs sometimes on larger spends, it’s best to have picked P2TR, although.
Shopper in a round Bitcoin economic system
One other exception could be a person that lives within the Bitcoin round economic system. You get your wage in bitcoin a couple of times a month and peel all of your funds off from that over the remainder of the time. On this case additionally, you would possibly create change 6× as usually because the variety of occasions that you’ve got a second enter. In that case, you’d be capable of save as much as 1.5% through the use of P2WPKH as a substitute of P2TR.
Alternate/Brokerage
If you happen to 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 usually have a number of inputs, however solely require a single change output to facilitate many withdrawals. Once you consolidate leftover small inputs, you achieve this at opportune moments with low feerates, and the numerous smaller inputs simply outweigh the creation of 1 heavier output in your consolidation transaction. Once you do must 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.
Conclusion: P2TR is cheaper in nearly each state of affairs
Whereas it’s affordable to attend with switching whereas particularly exchanges are nonetheless dragging their feets to allow assist for sending to P2TR outputs, simply from a price perspective, P2TR finally ends up being cheaper in nearly each state of affairs. Moreover, if you must create transactions at excessive feerates sometimes, the lower-weight inputs will save price. General, you’d save as much as 15.4% in transaction charges through the use of P2TR as a substitute of P2WPKH. If you happen to make vastly extra small funds than you obtain funds, you might save as much as 1.5% by sticking to P2WPKH.