topic How well does "What-If" work for estimating next year's taxes? in Get your taxes done using TurboTax

How well does "What-If" work for estimating next year's taxes?

Click — Tue, 24 Feb 2026 06:59:15 GMT

I've always used the Glenn Reeves spreadsheets to assist in tax planning for next year, and then stumbled across the "What-If" form in desktop TurboTax. It appears to give me what I'm looking for once I check the box to "use 2023 tax rates" and fill in my estimates.

However, I'm a bit concerned that something as simple as Standard Deduction isn't being populated with the right number. It is showing 27,700 even though both taxpayers MFJ have ages listed on lines 3 and 4 over 65. The number should be 30,700. TurboTax has all updates and these numbers for 2023 have been known since late 2022.

I'm not really asking about this one specific issue (which I work around with override), but the more general question as to whether the What-If form is still maintained. Is it relatively trustworthy? I understand the estimates are only as good as the estimates I'm supplying, and What-If doesn't cover all the tax situations that the full product will when released, etc. But am I better off with this or with the spreadsheets? By the way, once the standard deduction is overridden, the resulting tax matches my spreadsheets, so I think the tax tables are correctly updated.

Re: How well does "What-If" work for estimating next year's taxes?

Bsch4477 — Sun, 09 Jul 2023 15:01:49 GMT

Yes, the result depends upon the accuracy of the input and you have identified one inaccuracy. I have used What-if for many years and find it close enough to plan my withholding.

Re: How well does "What-If" work for estimating next year's taxes?

DoninGA — Sun, 09 Jul 2023 16:04:41 GMT

@Click That is odd you are seeing an incorrect Standard Deduction for 2023 using the What-If worksheet.

I am using the 2022 Premier edition for Windows version 022.000.0738 and on my worksheet for Column 2 with the 2023 tax rates selected it shows 30,700 for MFJ when both are age 65 or older.

If you are using Windows check your version. Click on Help at the top of the screen then click on About TurboTax and then the Version tab.

Re: How well does "What-If" work for estimating next year's taxes?

NCperson — Sun, 09 Jul 2023 16:07:46 GMT

@Click personally, i just use this website for "what if" - it is quite accurate.

https://www.dinkytown.net/java/1040-tax-calculator.html

Re: How well does "What-If" work for estimating next year's taxes?

Bsch4477 — Sun, 09 Jul 2023 16:35:08 GMT

@NCperson Thanks for sharing. I’ll try it.

Re: How well does "What-If" work for estimating next year's taxes?

Click — Sun, 09 Jul 2023 16:38:22 GMT

Ah .. I see the issue. I overlooked Line 38 of What-If where you have to manually enter number of boxes checked. I assumed that since TT already knows the correct ages, it would have entered that for me.

Re: How well does "What-If" work for estimating next year's taxes?

Click — Sun, 09 Jul 2023 16:40:33 GMT

Thanks. I'll have a look at DinkyTown. I guess if you clear cookies at some point you have to start all over. But it is still good to validate other the spreadsheet method.