Free, accurate calculators — verified against official sources

Every calculator on CalcMeadow documents its formula and cites the official source it was verified against, so you can trust the number you get.

• Chronological Age Calculator

  Compute exact chronological age in years, months, and days for speech-language pathology and educational testing.

• 13th Month Pay Calculator (Philippines)

  DOLE-compliant 13th month pay computation, including prorated pay for mid-year hires and unpaid absences.

• VTU CGPA to Percentage Calculator

  Convert VTU CGPA to percentage using the official VTU formula: (CGPA − 0.75) × 10.

• Nigeria Income Tax Calculator 2026

  Personal income tax under the Nigeria Tax Act 2025 (effective January 2026), including rent relief.

• Asian BMI Calculator

  BMI with WHO Asian-Pacific cutoffs — the standard BMI categories don't apply equally to Asian populations.