How we calculate your salary

Rules: mx-payroll-2026.1.0 · Sources reviewed October 1, 2026.

Scope

This tool estimates fully taxable, fixed ordinary pay for a private-sector employee enrolled in Mexico’s IMSS system. We assume full-time work, one employer, no absences and minimum statutory benefits. It is not a payroll liquidation or annual tax return. It does not cover every tax situation of people living in Mexico, such as independent contractors paid by overseas clients.

Income tax (ISR) and employment subsidy

We apply SAT Anexo 8 withholding tables, section B: I (daily), II (7 days), IV (15 days) and V (monthly). ISR = fixed quota + (salary − lower bracket limit) × marginal rate. Monetary components are rounded to cents. Quincenal means 15 days, not every 14 days.

From February, the eligible monthly subsidy is monthly UMA × 15.02%. January uses 2025 UMA × 15.59%. With the published UMA, this gives MXN $535.65 for February–December and $536.21 for January. The approximate $536.22 stated in the decree’s explanatory text does not replace its operative formula.

The monthly income ceiling is $11,492.66. For shorter pay periods, we assume monthly-equivalent income = salary / days × 30.4 and prorate the subsidy by days / 30.4. Actual eligibility requires aggregating all income in the calendar month. The applied subsidy cannot exceed ISR; unused credit is not paid in cash.

When ordinary income is exactly the region’s minimum wage and no other income is received, we withhold no ISR under Article 96. To estimate daily salary, monthly pay is divided by 30, 15-day pay by 15, weekly pay by 7 and daily pay by 1. Under this convention, monthly minimum wages are $9,451.20 in the general zone and $13,226.10 in the Northern Border Free Zone. Lower salaries are flagged as outside our full-time assumption.

Employee social security contribution (IMSS)

Integrated daily salary = daily salary × [1 + (15 days of aguinaldo + vacation days × 25%) / 365]. Vacation days are 12 for less than one year and the first completed year, then 14, 16, 18 and 20 for years 2–5; years 6–10 use 22, increasing by two days for each subsequent five-year block.

The daily contribution base (SBC) is integrated salary, with a regional minimum-wage floor and a cap of 25 UMA. Daily UMA is $113.14 in January and $117.31 from February. Daily employee contribution = SBC × 2.375% + max(SBC − 3 UMA, 0) × 0.4%. The 2.375% includes cash benefits 0.25%, pensioner medical expenses 0.375%, disability and life 0.625%, and old-age/unemployment insurance 1.125% (Social Security Law Articles 25, 107, 147 and 168; excess contribution under Article 106 and the nineteenth transitional article).

For monthly pay, IMSS uses the selected month’s actual calendar days. Shorter periods use 15, 7 or 1 day and are assumed to fall entirely within that month. At minimum-wage-only pay, the employer covers the worker’s contribution (Article 36). We do not model employer contributions, automatic INFONAVIT loan deductions, variable pay, absences or bimonthly payroll adjustments.

Net-to-gross calculation and limits

We search for the lowest gross salary, in cents, that reaches your target take-home pay. Tax brackets, subsidy cutoffs and minimum-wage exemptions are searched separately. Some targets have multiple solutions or no exact solution because of jumps. We show the difference if it exceeds one cent. The limit is $10,000,000 per pay period and 0–50 completed years of service.

Other deductions are subtracted after tax and do not reduce the taxable salary. Negative net income is displayed with a warning. These deductions are not personal tax-return deductions.

Official sources

If your benefits or employment arrangement differ, confirm your figures with your payroll team before making a decision.