How to calculate ESI, exactly
ESI's arithmetic is simple (0.75% plus 3.25% of gross), but its coverage rules are where payrolls go wrong. This guide covers both: the calculation and the contribution-period logic that governs who contributes when.
Rates and thresholds re-verified 27 July 2026. Statutory figures change by notification, so always confirm against the current official source before acting.
The rule in one paragraph
Employees earning gross wages up to ₹21,000 a month (₹25,000 for persons with disability) are covered by ESI: the employee contributes 0.75% of gross wages and the employer 3.25%, a total of 4%, deposited by the 15th of the following month. 'Gross wages' here is broad: basic, DA, HRA, and most regularly paid allowances enter the base, which makes ESI the contribution most often under-computed when allowances are paid informally. Coverage brings real benefits: medical care for the employee and dependants, sickness and maternity cash benefits, and disablement cover.
The contribution-period rule everyone trips on
ESI runs on two contribution periods, April to September and October to March. An employee covered at the start of a period stays covered for the entire period even if a raise takes their wages past ₹21,000 mid-period, with contributions continuing on the full higher wage. Exit from coverage happens only at the period boundary. The symmetric error (stopping deductions the month of the raise) is under-remittance that surfaces at reconciliation; the correct behaviour is to keep contributing until September or March and stop then.
Calculating a month, step by step
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1
Establish coverage
Check each employee's gross wage against the ₹21,000 ceiling as at the start of the current contribution period, that snapshot, not this month's wage, decides whether they contribute this month.
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2
Fix the wage base
Take the month's actual gross, including allowances, and including overtime for contribution purposes, pro-rated for the days actually on the rolls.
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3
Compute both sides
Employee: 0.75% of the base, rounded per ESIC's rounding convention. Employer: 3.25% of the base. The employee's share is the payslip deduction; the employer's accrues to the challan.
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4
Handle joiners and leavers
A joiner within the ceiling starts contributing from day one; coverage is immediate, not from the next period. A leaver contributes on their final wages through the last working day, and their settlement reflects it.
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5
Deposit and file by the 15th
Consolidate contributions, generate the monthly file, and pay through the ESIC portal by the 15th. Keep the challan reference against the month; it is the artifact inspections sample first.
A worked example
An associate earns ₹19,500 gross in April: employee ESI ₹147 (0.75%), employer ₹634 (3.25%). In July she gets a raise to ₹23,000. Correct treatment: contributions continue on ₹23,000 (₹173 and ₹748) through September, because April's coverage holds for the period; from October she exits coverage and the ESI lines end. The wrong-but-common treatment stops her ESI in July, leaving three months of under-remittance on the establishment. A second employee earning ₹19,500 plus ₹2,400 of overtime contributes on ₹21,900 that month but remains covered, because overtime never counts toward the exit test. Both cases left the same artifact behind: a contribution trail that reconciles to the payslips, which is what an ESIC inspection actually reads.
Figures are illustrative, for mechanism only. Verify current rates and your own structure before relying on any number.
Where ESI computations actually go wrong
The classic errors are coverage errors, not arithmetic ones. Stopping deductions the month a raise crosses ₹21,000: the contribution period says continue to its end. Testing coverage against a bonus-inflated month: the period-start wage governs. Excluding regularly paid allowances from the base, when ESI's gross is broad, and a 'conveyance top-up' paid to everyone monthly is almost certainly wages. And missing day-one coverage for joiners: ESI has no waiting period, so a joiner's first payslip must carry the deduction. Each error is small monthly and large cumulatively, because ESIC reconciliation looks at periods, not months.
The benefits side employers should actually know
Deducting correctly is half the duty; the other half is not obstructing benefits. Employees claim sickness benefit through ESIC with certification, maternity benefit at full standardised wage for 26 weeks (paid by ESIC, not the employer, for covered employees, a real relief for small establishments), and medical care for dependants. The employer's role is accurate, timely contribution and cooperation with records: an employee denied a benefit because contributions were missing or late is the dispute that escalates fastest, and the one clean records make impossible.
When employees cross out of ESI: the handover problem
An employee exiting ESI coverage at a period boundary loses ESIC medical cover from that point, which is precisely when group health insurance should pick them up. Well-run establishments treat the ₹21,000 crossing as an HR event, not just a payroll one: the October and April coverage transitions are checked, the insurance enrolment follows, and the employee is told what changed. The payroll system's contribution-period tracking is what makes the event visible in advance; the humane handover is what you do with the visibility. An employee who discovers mid-hospitalisation that neither ESIC nor the group policy covers them is a failure no payslip accuracy compensates for.
How payroll software applies this
PeopleDeck tracks each employee's contribution-period status so coverage decisions are made by the rule, not by this month's payslip: raises mid-period keep contributing, exits happen at the boundary, joiners start day one, and the monthly contribution files generate from the approved run for upload by the 15th. The ₹21,000 test, the overtime nuance and the pro-rata cases are all engine behaviour rather than analyst memory.
Go deeper: PF & ESI compliance · Statutory compliance · The payroll engine
Primary sources: ESIC · Ministry of Labour & Employment
Maintained by Databus Technology Solutions against the source notifications; the verification date above is refreshed whenever a figure changes. This guide explains rules and mechanics; it is not legal or tax advice. PeopleDeck applies statutory rates and generates upload-ready files; it never files returns on your behalf, and positions on contested questions belong with your consultant.
Frequently asked questions
Is ESI calculated on basic or gross?
On gross wages — essentially everything paid regularly except a few exclusions like washing allowance in specified cases. This is the opposite of PF (basic + DA), and mixing up the two bases is a classic spreadsheet error.
What happens when wages cross ₹21,000 mid-year?
Coverage continues to the end of the running contribution period (September or March), with contributions on the actual higher wage. Only from the next period does the employee exit ESI, and their payslip's ESI line should disappear exactly then, not earlier.
Do overtime and incentives attract ESI?
Overtime attracts contributions when paid but does not count toward the ₹21,000 coverage test, an employee is not pushed out of coverage by overtime. Regularly paid incentives generally enter the wage base; one-off annual payments generally do not. Borderline components deserve a consultant's confirmation.
What are the ESI deadlines?
Monthly contributions are due by the 15th of the following month, filed through the ESIC portal. The two contribution periods also carry return obligations; a payroll system generates the contribution files from each approved run.
Does every establishment have to register for ESI?
Registration triggers at 10 employees in most states (20 in some) in implemented areas — thresholds and area notifications vary, so verify your state's position. Once registered, coverage follows wages, not preference.
What does the employee actually get for the 4%?
Full medical care for self and dependants through ESIC facilities, sickness benefit at about 70% of wages for certified sickness, 26 weeks of maternity benefit, disablement and dependants' benefits. For covered employees, it is substantial insurance for the money.
ESI right through every contribution period.
Applied on every payslip, files generated for upload — per employee, per month.
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