Mexican ISR Income Tax Calculator

The Article 96 monthly tariff, with the one thing every other calculator hides — your marginal rate is not the rate you actually pay.

Reference table

Monthly taxable income	ISR for the month	Income after ISR	Marginal rate
1,000	MX$30.57	MX$969.43	6.4% — on the excess over your bracket floor
2,000	MX$94.57	MX$1,905.43	6.4% — on the excess over your bracket floor
2,500	MX$126.57	MX$2,373.43	6.4% — on the excess over your bracket floor
5,000	MX$286.57	MX$4,713.43	6.4% — on the excess over your bracket floor
7,500	MX$498.90	MX$7,001.10	10.88% — on the excess over your bracket floor
10,000	MX$770.90	MX$9,229.10	10.88% — on the excess over your bracket floor
12,500	MX$1,113.15	MX$11,386.85	16% — on the excess over your bracket floor
15,000	MX$1,552.78	MX$13,447.22	17.92% — on the excess over your bracket floor
20,000	MX$2,604.00	MX$17,396.00	21.36% — on the excess over your bracket floor
25,000	MX$3,672.00	MX$21,328.00	21.36% — on the excess over your bracket floor
30,000	MX$4,740.00	MX$25,260.00	21.36% — on the excess over your bracket floor
40,000	MX$7,065.30	MX$32,934.70	23.52% — on the excess over your bracket floor
50,000	MX$8,463.50	MX$41,536.50	30% — on the excess over your bracket floor
75,000	MX$15,963.50	MX$59,036.50	30% — on the excess over your bracket floor
100,000	MX$23,583.62	MX$76,416.38	32% — on the excess over your bracket floor

📋 The Article 96 Tariff

Up to $746.041.92%
Up to $11,128.016.40% and 10.88%
Up to $15,487.7116.00% and 17.92%
Up to $31,236.4921.36%
Up to $93,993.9023.52% and 30.00%
Above $375,975.6135.00%

Reading the Tariff Correctly

The rate applies only to what exceeds your bracket's lower limit, never to the whole income. That is why a raise can never leave you with less.
The fixed fee is the tax already accumulated from every bracket below yours. It is not an extra charge on top.
Your effective rate — tax divided by income — is always lower than your marginal rate, and it is the number that actually matters.
The employment subsidy is deducted after the tax is worked out, and its amount is set by decree, so take it from your payslip.

One Tariff, Eleven Brackets

Article 96 of the Ley del Impuesto Sobre la Renta sets the monthly tariff that every employer in Mexico applies to wages. It has eleven brackets, and each one carries three numbers: a lower limit, a fixed fee, and a rate. The calculation is always the same — find the bracket your income falls into, take its fixed fee, and add the rate applied to the amount by which your income exceeds the lower limit. The fixed fee is not an additional charge invented by the tax authority; it is simply the tax that all the brackets beneath yours have already produced, pre-computed so the employer does not have to work through them one at a time. Understanding that single point removes most of the confusion the tariff generates.

Why Your Rate Is Not Your Rate

The most persistent myth in Mexican payroll is that crossing into a higher bracket can leave you worse off. It cannot, and the structure of the tariff is why. If you earn 31,000 pesos a month you are in the 21.36% bracket, but that rate applies only to the 15,512 pesos above the bracket's floor — everything below is taxed at the lower rates that came before, already rolled into the fixed fee. Your effective rate, the tax divided by the whole income, comes out around 16%. Earn a peso more and only that peso is exposed to the higher rate. This calculator shows both numbers together precisely because seeing them apart is what creates the myth: the marginal rate describes your next peso, the effective rate describes all of them.

What Is Not Taxed

The Christmas bonus is exempt up to 30 UMA, which is why the aguinaldo is taxed on far less than its full amount.
The vacation premium and the annual profit share are each exempt up to 15 UMA.
Overtime within the legal limit is exempt for workers on the minimum wage, and half-exempt up to 5 UMA a week for others.
Employer contributions to social security are not your income and are not taxed to you.
Severance pay has its own regime with a separate exemption of 90 UMA per year of service.
Food vouchers and savings funds are exempt within limits that depend on the employer's own deduction rules.

How the Calculation Goes Wrong

Applying the bracket's rate to the whole income instead of only the excess. It overstates the tax enormously.
Adding the fixed fee and also taxing the amount the fee already covers. The same pesos get charged twice.
Using the annual tariff on a monthly wage. The two tables exist separately for a reason.
Treating the marginal rate as the amount withheld. It is the rate on your next peso, not on your salary.
Forgetting the employment subsidy, which reduces the withholding for lower incomes and is set by decree.
Applying the wages tariff to income that is not wages. Fees, rent and dividends have their own rules.

Worked Examples

Two brackets, step by step

$25,000 a month

Bracket: 15,487.72 to 31,236.49, rate 21.36%
Fixed fee 1,640.18 + (25,000 − 15,487.72) × 21.36%
1,640.18 + 2,031.82

$3,672.00 — an effective 14.69%

$12,000 a month

Bracket: 11,128.02 to 12,935.82, rate 16.00%
Fixed fee 893.63 + (12,000 − 11,128.02) × 16%
893.63 + 139.52

$1,033.15 — an effective 8.61%

Frequently Asked Questions

How is ISR calculated on wages in Mexico?

Find your bracket in the Article 96 monthly tariff, take its fixed fee, and add the bracket's rate applied to the amount by which your income exceeds the bracket's lower limit. The employment subsidy, if any, is then subtracted.

What is the lower limit and the fixed fee?

The lower limit is where your bracket begins. The fixed fee is the tax already produced by every bracket beneath it, pre-computed so it does not have to be recalculated each time. Neither is an extra charge.

Can a raise leave me with less money?

No. The higher rate applies only to the pesos above the new bracket's floor, never to your whole income. Everything below keeps being taxed exactly as it was, which is what the fixed fee represents.

What is the difference between marginal and effective rate?

The marginal rate is the rate on your next peso — the rate of your current bracket. The effective rate is the tax divided by your whole income, and it is always lower. On 50,000 pesos a month the marginal rate is 30% and the effective is around 17%.

Why doesn't this match the withholding on my payslip?

The employment subsidy, food vouchers, savings-fund contributions and the treatment of a bonus month can all shift the figure. This page uses the plain Article 96 tariff, which is the base every one of those adjustments is applied to.

Is there a separate tariff for fortnightly pay?

Yes. The SAT publishes a tariff for each payment period — weekly, fortnightly, monthly, annual. This page uses the monthly one, which is the reference all the others are derived from and the one most people are trying to check.