Which AI Calculates Taxes Appropriately?

A number of readers requested me whether or not they may use AI to calculate taxes after studying my earlier submit AI Offers Higher Solutions Than Google. They need a tax projection to assist with setting tax withholding, paying estimated taxes, or planning for Roth conversions.

My first response was that calculating taxes isn’t the very best use of AI, as a result of it falls underneath “verifiable information” and “newest improvement” classes. The retirement plan contribution limits, tax brackets, the utmost deduction quantities, and so forth., are all verifiable information. The IRS units them yearly, and they’re what they’re. Simply go to the IRS web site for the most recent numbers or Google. In the event you ask AI, it had higher get the most recent numbers on-line anyway, as a result of AI’s coaching lags.

Alternatively, tax guidelines are difficult. Even when you’ve all the most recent numbers from the IRS, you continue to want to use the advanced guidelines — what counts and what doesn’t, and which charges apply to which earnings. On-line tax calculators often don’t cowl the present yr till late within the yr, and they are often both too easy or too difficult. It might be good to have AI calculate taxes particularly for the sorts of earnings and deductions we have now: not too easy with solely restricted inputs, and never too difficult with all the things underneath the solar.

The Quiz

I believed I might take a look at how properly AI calculates taxes. I got here up with this quiz query:

Jill, single, age 63, has these incomes in 2026:

• $30,000 from Social Safety
• $10,000 from curiosity and pre-tax IRA withdrawals
• $37,000 from certified dividends and long-term capital beneficial properties
• $1,000 from muni bond curiosity

Jill contributes $4,400 to her HSA and donates $1,500 in money to charities. What’s Jill’s federal earnings tax in 2026?

I designed this query fastidiously to cowl a number of calculations. Lower than 85% of Social Safety is taxable. The earnings consists of odd earnings, tax-exempt earnings, and funding earnings taxed at preferential charges. Peculiar earnings goes throughout two tax brackets. So does funding earnings. One deduction is above-the-line, and the opposite is below-the-line.

I added these directions to encourage AI to get the most recent tax numbers from the IRS:

It’s necessary to calculate it precisely. Please use tax quantities just for 2026 and solely from official IRS sources.

Preliminary Outcomes

I despatched the quiz to all 4 main AI chatbots. I solely used the free model in each, with the free Considering, Professional, or Knowledgeable mode enabled. I in contrast the solutions to the proper end result from my calculator in Calculator: How A lot of My Social Safety Advantages Is Taxable?

My quiz was too exhausting! All 4 main AI fashions failed to present the proper reply. The $1,500 money donation threw them off. It falls squarely within the “newest improvement” class. The charity donation deduction for non-itemizers is new. The AI fashions all have “donations are deductible solely whenever you itemize” imprinted of their coaching. Gemini, Claude, and Grok all would have given the proper reply if I hadn’t included the money donation. ChatGPT was off on how a lot of Social Safety is taxable.

If you see AI not providing you with a deduction, you may level it out. I adopted up with this trace:

I heard that money donations are deductible for folks utilizing the usual deduction, beginning in 2026, as much as a restrict.

I additionally added this for ChatGPT:

One other AI mannequin calculated a distinct quantity for the way a lot Social Safety is taxable. Please double-check your calculation to see who’s proper.

Spherical 2

All chatbots double-checked and revised their solutions.

ChatGPT and Claude obtained the proper reply. Gemini and Grok handled the money donation deduction as above-the-line and used it to cut back the Social Safety taxable quantity.

I requested Gemini and Grok to make clear which merchandise needs to be included within the calculation and which shouldn’t be. Gemini didn’t notice its mistake. Grok refused to reply as a result of I reached the message restrict for not having an account.

Listed here are the total chat transcripts in the event you’re :

https://chatgpt.com/share/69bf73fb-db44-8004-9905-b77b56fbb6ce

https://gemini.google.com/share/795bdad9f5ad

https://claude.ai/share/ef62408a-6502-4d70-82be-6ea46a4a4cc3

(No sharable hyperlink for Grok as a result of I don’t have an account.)

Impressions

I don’t suppose we will draw definitive conclusions based mostly on just one take a look at. I name these impressions.

1. Whether or not AI can calculate taxes appropriately will depend on the complexity. 3 out of 4 main chatbots would’ve given the proper reply in a single go if the query didn’t embrace the brand new and tough charity donation deduction.

2. AI works higher whenever you proceed the dialog. Each ChatGPT and Claude reached the proper reply after I requested them to double-check.

3. It takes little effort to ship the identical query to 2 or extra AI fashions. You don’t have to know which AI is correct whenever you get totally different solutions. You possibly can inform one AI that one other AI stated one thing totally different. It’ll take a second move and re-examine.

4. AI was mistaken as a result of human sources have been mistaken. Gemini and Grok handled the donation deduction as above-the-line as a result of many human sources incorrectly referred to as it above-the-line. In the event you Googled, you’d encounter these incorrect sources too. ChatGPT and Claude used extra dependable sources and appropriately recognized the distinction between above-the-line and never requiring itemizing deductions.

5. An internet tax calculator is quicker and extra correct if you already know which one to make use of. That’s a giant “if.” Solely saying “Don’t use AI as a result of it’s typically mistaken” doesn’t say the place you will see that extra dependable sources.

As a lot as I’d prefer to see everybody use my tax calculatorlet’s face it: 99.99% of individuals don’t know that I exist. They’ve little probability to search out the few sources that do it precisely as a result of Google doesn’t rank tax calculators by accuracy. In need of discovering the nice sources, the outcomes from AI aren’t that unhealthy (see #1).

6. Even when AI was mistaken in some nuances, its common strategy was appropriate. All 4 AI chatbots adopted these appropriate steps:

• Calculate how a lot of Social Safety is taxable
• Calculate AGI
• Calculate taxable earnings
• Separate odd earnings and preferential funding earnings, and know the way they stack
• Apply totally different tax brackets

These are what I name “frequent data of an insider.” You possibly can be taught these steps from AI in the event you’re not conversant in tax calculations. That’s extra beneficial than simply having a last quantity. An internet tax calculator provides you a quantity however doesn’t clarify the steps. AI is a greater instrument in the event you’re extra taken with studying find out how to fish than getting a fish.