Methodology
Last updated
How we build each calculator
- Every tax slab, limit and rate comes from an official source whose relevant provisions we read, and is recorded with its link, the exact provision and the date we checked it.
- Rules are kept separate from code, so a Budget change is a single update.
- A calculator that depends on a rule we could not verify is not listed or linked until it is verified.
- Every formula has automated tests, including hand-checked examples, slab boundaries and extreme inputs.
- We do not recommend funds, stocks, insurers or policies.
Official sources and when we checked them
Income tax rates, rebate, surcharge, cess
- Primary source
- Income-tax Act, 2025 (No. 30 of 2025), Gazette of India, 21 Aug 2025: s.202(1) Table (new regime slabs), s.202(2) (disallowed deductions)
- Income-tax Act, 2025 (No. 30 of 2025), Gazette of India, 21 Aug 2025: s.19(1) Table Sl. Nos. 1–2 (professional tax, standard deduction)
- Income-tax Act, 2025 (No. 30 of 2025), Gazette of India, 21 Aug 2025: s.156(1)–(3) (rebate)
- Income-tax Act, 2025 (No. 30 of 2025), Gazette of India, 21 Aug 2025: s.124(1)–(2) (employer NPS), s.17(1)(h) (₹7.5 lakh cap), s.516 (rounding)
- Finance Act, 2026 (No. 4 of 2026), Gazette of India, 30 Mar 2026: s.3(1) and First Schedule Part I-B Para A (old regime slabs)
- Finance Act, 2026 (No. 4 of 2026), Gazette of India, 30 Mar 2026: First Schedule Part I-B Para F Tables 1–2 (old regime surcharge, marginal relief)
- Finance Act, 2026 (No. 4 of 2026), Gazette of India, 30 Mar 2026: s.3(4) Table Sl. No. 10 and s.3(5) (new regime surcharge, marginal relief)
- Finance Act, 2026 (No. 4 of 2026), Gazette of India, 30 Mar 2026: s.3(15) (4% Health and Education Cess)
- Finance Act, 2026 (No. 4 of 2026), Gazette of India, 30 Mar 2026: s.56 (omits s.202(2)(a)(iii), SEZ deduction; no effect on salaried)
- Finance Bill 2026, Memorandum explaining the provisions: Part II (no change in rates for tax year 2026-27)
Old-regime deductions (s.123, s.124(3), s.126, home loan)
- Primary source
- Income-tax Act, 2025 (No. 30 of 2025), Gazette of India, 21 Aug 2025: s.123, s.124(3)–(5), s.126(2)–(8), s.22(2), (5)
- Finance Act, 2026 (No. 4 of 2026), Gazette of India, 30 Mar 2026: No amendments to ss.22(2), 123, 124, 126
HRA exemption
- Primary source
- Income-tax Rules, 2026, CBDT Notification No. 22/2026, G.S.R. 198(E), 20 Mar 2026: Rule 279 (Gazette p.1776)
- Income-tax Rules, 2026, CBDT Notification No. 22/2026, G.S.R. 198(E), 20 Mar 2026: Rule 205 Table Sl. No. 1
- Income-tax Act, 2025 (No. 30 of 2025), Gazette of India, 21 Aug 2025: Schedule III Table Sl. No. 11; s.202(2)(a)(i)
EPF contributions and wage ceiling
- Primary source
- Code on Social Security, 2020 (No. 36 of 2020), Gazette text via Ministry of Labour: s.16(1)(a) and first proviso (10%, or 12% where notified)
- Code on Social Security, 2020 (No. 36 of 2020), Gazette text via Ministry of Labour: s.16(1)(b)(i) (EPS up to 8⅓% of wages)
- PIB: Government makes the four Labour Codes effective (21 Nov 2025): Codes in force from 21 Nov 2025
- PIB: Cabinet approves higher EPFO wage ceiling of ₹25,000 (16 Sep 2026): ₹25,000 ceiling from 17 Sep 2026
- PIB: EPFO raises wage ceiling to ₹25,000, Gazette S.O. 5109(E) (23 Sep 2026): Gazette S.O. 5109(E); EPS max ₹2,083/month
- Ministry of Labour & Employment: FAQs on Labour Codes (30 Dec 2025): FAQs 2–7 (wages definition and 50% rule, worked example)
- Ministry of Labour & Employment: Additional FAQs on Labour Codes (16 Mar 2026): FAQ 1 (what counts in total remuneration)
EPF interest rate
Gratuity payout and exemption
- Primary source
- Code on Social Security, 2020 (No. 36 of 2020), Gazette text via Ministry of Labour: s.53(1)–(3), Explanation 3; s.54; s.164(2)(a) (saves earlier notifications)
- PIB: Income tax exemption for gratuity enhanced up to ₹20 lakh (7 Mar 2019): ₹20 lakh payout ceiling notified 29 Mar 2018; ₹20 lakh tax exemption
- Income-tax Act, 2025 (No. 30 of 2025), Gazette of India, 21 Aug 2025: s.19(1) Table Sl. Nos. 3–6; s.536(2)(j) (1961-Act notifications continue)
- Ministry of Labour & Employment: FAQs on Labour Codes (30 Dec 2025): FAQs 8–9 (Code gratuity applies from 21 Nov 2025)
RSU/ESOP perquisites and capital gains
- Primary source
- Income-tax Act, 2025 (No. 30 of 2025), Gazette of India, 21 Aug 2025: s.17(1)(d), s.17(2)(e)–(h) (perquisite on specified securities)
- Income-tax Rules, 2026, CBDT Notification No. 22/2026, G.S.R. 198(E), 20 Mar 2026: Rule 15(6)–(8) (FMV on exercise date)
- Income-tax Act, 2025 (No. 30 of 2025), Gazette of India, 21 Aug 2025: s.73(1) Table Sl. No. 4 (cost = FMV taken for perquisite)
- Income-tax Act, 2025 (No. 30 of 2025), Gazette of India, 21 Aug 2025: s.2(101) (holding periods), ss.196–198 (rates, ₹1.25 lakh exemption)
- Income-tax Act, 2025 (No. 30 of 2025), Gazette of India, 21 Aug 2025: s.140(16)(b), s.289(3), s.391(2), s.392(3) (start-up deferral)
- Finance Act, 2026 (No. 4 of 2026), Gazette of India, 30 Mar 2026: s.46 (start-up turnover limit ₹100 crore → ₹300 crore); ss.196–198 not amended
PPF rate and limits
- Primary source
- National Savings Institute (MoF): PPF interest rate since inception: 7.1% for 01.04.2020 to 30.09.2026
- DEA Office Memorandum F.No.1/4/2019-NS dated 30.09.2026 (Q3 FY 2026-27): Rates for 1 Oct–31 Dec 2026 unchanged from Q2
- National Savings Institute: Public Provident Fund Account: Deposit limits, 15-year maturity, 5-year extension blocks, loan from year 3 to 6, withdrawal from year 7
- Public Provident Fund Scheme, 2019 (Gazette notification, via India Post): Para 7(1)–(2): interest on the lowest balance between the close of the 5th day and month end, credited yearly
GST rates
- Primary source
- PIB: Recommendations of the 56th GST Council meeting (3 Sep 2025): Two-rate structure 5% / 18% plus 40% de-merit rate, from 22 Sep 2025
Car insurance IDV depreciation
8th Pay Commission status
- Primary source
- PIB: Cabinet approves Terms of Reference of 8th CPC (28 Oct 2025): 18 months to report; effect normally expected from 01.01.2026
- 8th Central Pay Commission official site: Constituted 3 Nov 2025; state visits continuing in Oct 2026; no report published
Central Government DA
Professional tax: Maharashtra
Professional tax: Karnataka
- Primary source
- Karnataka Professional Tax portal: FAQ and notice on Feb instalment: Exempt below ₹25,000/month from 1/4/2023; ₹300 for February per Notification DPAL 08 SHASANA 2025 dated 15.04.2025
Professional tax: Telangana
Professional tax: West Bengal
Professional tax: Gujarat
Professional tax: Madhya Pradesh
Professional tax: Andhra Pradesh
Professional tax: Tamil Nadu (Chennai)
Conventions
- Tax year. FY 2026-27 is “tax year 2026-27”, the first year under the Income-tax Act, 2025. Section numbers refer to that Act, with the old section in brackets where helpful.
- Rounding. Taxable income and tax payable are rounded to the nearest ₹10 (section 516).
- Marginal relief. Applied for the new-regime rebate just above ₹12 lakh and for surcharge at ₹50 lakh, ₹1 crore, ₹2 crore and ₹5 crore, using the Finance Act, 2026 formula.
- EPF wage ceiling. ₹15,000 until August 2026 and ₹25,000 from September 2026 for annual totals; monthly figures use ₹25,000.
- Labour Code wages. If basic + DA is less than half of gross pay, PF and gratuity wages are raised to half of gross (variable pay and employer PF excluded). This can be switched off.
- Investments. SIP instalments are invested at the start of each period; the expected return is a compound annual rate; a daily SIP has 21 market days a month.
- Deposits. RDs compound quarterly; PPF deposits are assumed by 5 April each year.
- Insurance. Cover estimates are arithmetic on your own assumptions. They are not quotes.
How we check results
Income tax results were compared with the Income Tax Department’s advance calculator for tax year 2026-27 on 30 incomes, from nil to ₹6 crore. All matched to the rupee except in three documented cases: the department’s calculator does not round to ₹10; just above ₹2 crore it applies a flat 15% surcharge where the Finance Act’s marginal-relief formula gives a higher figure; and for the old regime above ₹5 crore it applies 25% where the Finance Act states 37%. In each case we follow the law as written.
What we do not model
- Income other than salary in the salary tools; capital gains surcharge relief; foreign tax credits.
- Floating loan rates, prepayment charges and fees.
- Employer-specific salary rules beyond the editable assumptions.
Updates
We review rules after every Union Budget and when a relevant notification is issued. Changes are listed on the changelog.