To do estimated taxes for 2024 and spouse died in 2023 should i file as single?

Yes, you should use the single filing status for 2024. When calculating your tax for 2024, add all the income you think you will receive, calculate the tax on the single filing status and then subtract any federal withholding you anticipate, use the balance to arrive at your estimated tax for the year.

If you should have an increase to your income at some point you can always add more to the next payment.  The following can be a guide if your income will increase over the 2023 tax year.

Generally, you can avoid the penalty if your total timely estimated payments and withholdings are greater than or equal to the lesser of:

• 90% of the total tax after credits for the current year, or
• 100% of the total tax after credits in the prior year
• See one exception below.

You can also avoid the penalty if the amount you owe is less than $1,000 as long as any estimated tax payments you made are timely.

Note: High-income taxpayers. If your adjusted gross income (line 11 of your 2023 Form 1040) is greater than $150,000 (or $75,000 if you're married and file a separate return from your spouse), you can avoid a penalty by paying at least 110% of your total tax from the prior year.

Sorry for your loss.  My husband died last year too.  Next year (for 2024) I will file as Single on a new return and not transfer from 2023.  My income didn't change at all so I will have a much higher tax as Single.  Figuring estimates is a chore.  I have the Desktop program and using the What-If worksheet.  

Then for 2023 (Joint return) I applied part of my refund to 2024.  First time I ever applied any.  But the IRS wrote me a letter saying they didn't know what to do with that amount.  Probably because my husband's ssn is deceased.  Wrote IRS back.  Hope it gets applied to my ssn.  It's messing up my estimates.  So I'm not including it as part of my estimates.   Guess I'll have a big refund next year.