Sri Lanka APIT Calculator — Monthly Employee Tax (2025/26)

The calculator implements the IRD's Table 01 (Monthly Tax on Regular Profits) for Year of Assessment 2025/26. The same monthly figure can be derived two equivalent ways, and this page runs both in parallel so you can see them match to the rupee:

1. Bracket walk (annual basis). Multiply your monthly gross by 12 to get annual gross. Subtract the personal relief of Rs 1,800,000 (Rs 150,000 a month) to get annual taxable income. Apply the progressive brackets in order, then divide by 12 to get the monthly APIT.
   • Rs 0 → Rs 1,000,000 : 6%
   • Rs 1,000,000 → Rs 1,500,000 : 18%
   • Rs 1,500,000 → Rs 2,000,000 : 24%
   • Rs 2,000,000 → Rs 2,500,000 : 30%
   • Above Rs 2,500,000 : 36%
2. Closed-form monthly formula (Table 01). The IRD publishes a per-bracket APIT = rate × M − constant formula so payroll software can short-circuit the bracket walk. The constants for Y/A 2025/26 are:
   • Rs 0 → Rs 150,000: rate 0%, constant Rs 0
   • Rs 150,000 → Rs 233,333: rate 6%, constant Rs 9,000
   • Rs 233,333 → Rs 275,000: rate 18%, constant Rs 37,000
   • Rs 275,000 → Rs 316,667: rate 24%, constant Rs 53,500
   • Rs 316,667 → Rs 358,333: rate 30%, constant Rs 72,500
   • Above Rs 358,333: rate 36%, constant Rs 94,000

The calculator runs both methods on every keystroke and surfaces a green “cross-check passed” line if they agree to the rupee. If you spot a divergence please email me — the brackets in this tool are kept in sync with the IRD's published tables, but new amendments do occasionally happen mid-year.

The optional “+ Bonus / lump-sum”mode implements the IRD's Table 02 procedure for a one-off payment. With the simplifying assumption that your monthly salary stays constant for the year and no earlier lump-sums have been paid YTD, the tax due on a lump-sum B is:

lumpSumTax = annualTax(monthlyGross × 12 + B) − annualTax(monthlyGross × 12)

For payslip-level accuracy when you have prior YTD figures, take the result here as a guide and reconcile against your employer's payroll system, which can use your actual month-by-month payment history.

Why the annual basis matters. APIT is a withholding mechanism, not a separate tax. The Rs 150,000 monthly relief and the six-figure slab widths only make sense once you annualise, because the personal relief of Rs 1,800,000and the brackets are defined per year of assessment, not per month. That is why a single large month — say a bonus month — can push you into a higher band for that month even though your regular salary sits comfortably in a lower one. The IRD's Table 02 method exists precisely to smooth that out: it charges the lump-sum at your projected marginal rate rather than spiking a single month's regular deduction. If your total earnings for the year end up lower than projected — for example you leave employment mid-year — your final liability from your annual return may be less than the APIT withheld, and the difference is refundable.

What counts as “regular profits from employment.” The figure you enter should be your gross cash remuneration for the month — basic salary plus fixed cash allowances that form part of your contractual pay. Statutory employee deductions such as your EPF contribution are not subtracted before APIT: APIT is calculated on gross, and EPF comes out separately. If you want to see the EPF and ETF side of your payslip, use the Sri Lanka EPF & ETF Calculator. For the full-year picture — including business income, rent, and other sources reconciled against your APIT credits — cross-check with the Sri Lanka Income Tax Calculator. And if part of your income is self-employed or freelance, that portion is settled through quarterly installments rather than APIT — the quarterly tax installment calculator covers those due dates.

Rounding and edge behaviour. The IRD convention is to round the monthly APIT to the nearest rupee, which this tool follows — so on rare boundary inputs the bracket walk and the closed-form formula can differ by up to one rupee before rounding, then agree once rounded. Salaries at or below the Rs 150,000 relief return zero APIT, but your employer must still register you and file a nil monthly schedule. Inputs are clamped to a sane maximum so that a mistyped figure never produces a nonsensical negative take-home.

• IRD — Tax Chart for Y/A 2025/26
• IRD — APIT Tax Table No. 01 (Monthly Tax Deductions from Regular Profits)
• IRD — APIT publications landing page (Tables 01, 02, 03)
• Inland Revenue Department of Sri Lanka — official site

Brackets, formulas, and worked-example values were last cross-checked against the IRD sources on 2026-05-16. The personal relief was raised from Rs 1,200,000 to Rs 1,800,000, and the 12% slab was removed, effective 1 April 2025 under the Inland Revenue (Amendment) Act No. 2 of 2025.