Was my furusato nozei calculation correct?

[Tkydon]

Hmm.. so it seems like the process to check how much furusato nozei reduced your tax bill is different if you did kakutei shinkoku.

So those fields seem to just be a part of your deduction. You then have to add the value of: ("total donation" - 2000) x income tax rate x 1.021 to it.

https://furu-sato.com/magazine/11491/

Hi @zeroshiki, do you have any idea if this calculation has changed this year or not?

I performed the same calculation and got a value higher than what I had actually donated!

The Tax Deduction you apply to your Taxable Income is the amount you would have to reduce your Taxable Income by that would produce the reduction in the Final Total Tax Payable equal to the Furusato Nozei Donation...

If your Marginal Tax Rate is 33% and the Reconstruction Tax on that is 0.21% of that or 0.693% (that is where the 1.0021 number above comes from), for a total of 33.693%, then in order to correctly account for the Donation in Pre-Tax Income Deduction, you would have to reduce your taxable income by

Donation / (1-0.33693)
or
Donation / 0.66307
or
Donation x 1.508136

to correctly account for the Furusato Nozei Donation paid, and reduce your Tax Bill correctly.