Sri Lanka Net Salary to Gross Salary Calculator — 2025/26

The calculator inverts the IRD's monthly APIT function. APIT is a piecewise-linear function of monthly gross — six bands, each with a single rate — and the 8% EPF employee deduction is linear. The sum of two piecewise-linear functions is itself piecewise-linear, so the inverse (gross given net) is also piecewise-linear and can be solved in closed form per band. No iteration, no trial-and-error.

The six monthly APIT bands (IRD Table 01)

For monthly remuneration G, APIT is computed using APIT = rate × G − constant inside each band:

• Rs 0 < G ≤ Rs 150,000 · rate 0% · constant Rs 0
• Rs 150,000 < G ≤ Rs 233,333 · rate 6% · constant Rs 9,000
• Rs 233,333 < G ≤ Rs 275,000 · rate 18% · constant Rs 37,000
• Rs 275,000 < G ≤ Rs 316,667 · rate 24% · constant Rs 53,500
• Rs 316,667 < G ≤ Rs 358,333 · rate 30% · constant Rs 72,500
• G > Rs 358,333 · rate 36% · constant Rs 94,000

The inverse, derived

Inside a band, monthly net N as a function of gross G is:

N = G − (rate × G − constant) − (8% × G) − other = G × (1 − rate − 0.08) + constant − other

Solving for G:

G = (N − constant + other) / (1 − rate − 0.08)

The calculator evaluates this formula for each of the six bands and picks the band where the resulting G lands inside its own (from, to] window — exactly one band qualifies for any valid net input. Bracket boundaries are handled inclusively on the upper edge with a small epsilon, so a target net that maps to a gross of Rs 233,333.33 (the top of the 6% slab) still resolves cleanly into that band rather than the next one up.

Round-trip verification

To prove the answer to itself, the solved gross is fed back through the same forward APIT walk used by induwara.lk's Sri Lanka income tax calculator. The recomputed net must equal the user's target net to within Rs 1 of floating-point rounding. The shield badge at the top of the calculator turns green only when this condition is met — if you see anything else, the inputs are out of range or have hit an unhandled edge case.

What's in scope, what isn't

The math covers regular monthly employment income only. Bonuses, arrears, and one-off lump sums use IRD Table 02 (cumulative annual position) and need a separate calculation. Secondary employment uses Table 03. Non-cash benefits like company car valuations or fuel allowances are taxable employment income under the IRD's benefits-in-kind rules but are not modelled in this v1 — add their cash-equivalent to your net target if you want them folded in. Employer-side contributions (12% EPF, 3% ETF) never touch the employee take-home equation and are explicitly excluded; use the EPF calculator if you need that view.

Why the brackets matter for negotiation

The gap between gross and net is non-linear because each extra rupee of gross may sit in a higher band than the last. Asking for a Rs 50,000 raise to lift your net by Rs 35,000 sounds reasonable — but if the new gross crosses the Rs 316,667 boundary, that raise actually has to be Rs 50,000 / (1 − 0.30 − 0.08) = Rs 80,645 to land you Rs 50,000 of extra net. This calculator surfaces that arithmetic so you can put a precise gross figure on a counter-offer instead of guessing.

Three scenarios with the math fully traced. Plug each target net into the calculator above — the bracket breakdown should match these figures to the rupee.

• IRD — Tax Chart for Y/A 2025/26
• IRD — APIT Tax Table No. 01 (Monthly Tax Deductions from Regular Profits)
• Central Bank of Sri Lanka — Employees' Provident Fund (EPF Act No. 15 of 1958)
• Inland Revenue Department of Sri Lanka — official site

The bracket constants and EPF rate on this page were last cross-checked against the official sources on 2026-05-16. They are imported from the same module that powers induwara.lk's forward Sri Lanka income tax calculator — when one moves, both move.