How We Calculate

Full transparency on every formula. Every calculator on CPF Calculator SG uses the methods documented below, based on CPF Board's published rates.

Last updated: May 2026 · Rates reflect 2026 CPF Board figures.

1. CPF Contribution Calculator

What it does

Shows how much CPF is deducted from your monthly salary, split between employer (ER) and employee (EE), and how the total is allocated to your Ordinary Account (OA), Special Account (SA), and Medisave Account (MA).

Input factors

Formula

cappedWage  = min(monthlyGrossWage, $8,000)

employerCPF = cappedWage × ER rate
employeeCPF = cappedWage × EE rate
totalCPF    = employerCPF + employeeCPF

OA = round(totalCPF × OA allocation %)
SA = round(totalCPF × SA allocation %)
MA = round(totalCPF × MA allocation %)

Contribution rates (Citizen / PR 3rd year onwards)

PR rates: 1st year ER 4% / EE 5% (total 9%); 2nd year ER 9% / EE 15% (total 24%). Allocation percentages remain the same as the age-group table. Source: CPF Board — Employer contribution rates

OA / SA / MA allocation ratios

2. CPF Interest Calculator

What it does

Projects how your OA, SA, and MA balances grow over time with CPF's guaranteed interest rates and the extra interest benefit.

Input factors

Interest rates

* Extra 1% applies to the first S$60,000 of combined balances. OA contribution to this S$60,000 pool is capped at S$20,000. Members aged 55+ receive an additional 1% on the first S$30,000 of combined balances (not yet modeled in this calculator). Source: CPF Board — Interest rates

Formula (yearly compound)

Each year:
  oaEligible     = min(OA balance, $20,000)
  eligiblePool   = min(oaEligible + SA + MA, $60,000)
  extraInterest  = eligiblePool × 1%

  // Distribute extra proportionally across eligible accounts
  oaExtra = (oaEligible / eligiblePool) × extraInterest
  saExtra = (SA / eligiblePool)        × extraInterest
  maExtra = (MA / eligiblePool)        × extraInterest

  oaInterest = OA × 2.5% + oaExtra
  saInterest = SA × 4.0% + saExtra
  maInterest = MA × 4.0% + maExtra

  OA += oaInterest   (compounds yearly)
  SA += saInterest
  MA += maInterest

3. CPF LIFE Payout Calculator

What it does

Estimates your monthly CPF LIFE payouts based on your Retirement Account (RA) balance and the plan you choose. CPF LIFE is a national annuity scheme that provides lifelong monthly payouts from age 65.

Input factors

Formula

Standard:    monthlyPayout = RA balance × 0.65%
Escalating:  monthlyPayout = RA balance × 0.54%  (increases 2% each year)
Basic:       monthlyPayout = RA balance × 0.58%

Annual payout = monthlyPayout × 12

The rates above are simplified estimates based on CPF Board's published payout figures for age-65 entry. Actual payouts depend on your age at join, sex, and prevailing interest rates. Source: CPF Board — CPF LIFE overview · CPF LIFE payout estimator

4. Retirement Sum Calculator

What it does

Projects your Retirement Account (RA) balance at age 55 and checks whether you're on track for the Basic (BRS), Full (FRS), or Enhanced (ERS) Retirement Sum.

Input factors

Retirement sums (2026)

Formula

yearsTo55 = max(55 − currentAge, 0)

// Monthly SA contribution based on age-group rates
saMonthly = min(salary, $8,000) × (ER% + EE%) × SA allocation %

// Project SA balance: 4% compound + monthly contributions
SA at 55 = SA × (1.04)^yearsTo55  +  saMonthly × 12 × yearsTo55
         (simplified: yearly compound with annual contribution)

// Project OA balance: 2.5% compound
OA at 55 = OA × (1.025)^yearsTo55

// At age 55: OA transfers to SA to form RA, up to FRS gap
transferAmount = min(OA at 55,  FRS − SA at 55)
RA = SA at 55 + transferAmount

Status:
  RA ≥ ERS  → "exceed"   (green)
  RA ≥ FRS  → "on-track" (blue)
  RA < FRS  → "short"    (red)

At age 55, your SA becomes your Retirement Account (RA). You may also transfer OA savings to your RA, up to the Full Retirement Sum. Source: CPF Board — Retirement sums

5. Tax Relief Calculator

What it does

Shows how much income tax you save by making a voluntary CPF top-up (up to S$8,000 per year for self top-up to SA/RA).

Input factors

Singapore 2026 tax brackets

Formula

taxWithout = progressiveTax(annualIncome)
taxWith    = progressiveTax(annualIncome − topUpAmount)
taxSaved   = taxWithout − taxWith
effectiveRate = (taxSaved / topUpAmount) × 100%

progressiveTax(income):
  tax = 0
  for each bracket (prev, max, rate):
    taxable = min(income, max) − prev
    tax += taxable × rate
  return tax

CPF top-ups qualify for tax relief under Section 14 of the Income Tax Act. Max S$8,000 for self top-up, additional S$8,000 for top-ups to family members. Source: IRAS — CPF Tax Relief

Official CPF Resources

Always verify against official sources. These links go directly to cpf.gov.sg and iras.gov.sg.