ProRataCalculatorProRata

About ProRataCalculator

Last updated: February 2026

Our Mission

ProRataCalculator provides free, accurate pro rata salary calculators and employment guides for UK workers. With over 8.7 million part-time workers in the UK (ONS 2024), we believe everyone deserves clear, accessible tools to understand their pay.

Our calculators cover pro rata salary, term-time pay, overtime, day rates, FTE, holiday pay, salary sacrifice, and London weighting — covering the most common employment calculations UK workers need.

Our Methodology

Every calculator on this site follows standard UK employment formulas as used by HR departments, payroll providers, and HMRC:

  • Pro rata formula: Full-Time Salary × (Actual Hours ÷ Full-Time Hours) — the standard method used by UK employers
  • Term-time adjustment: Annual Salary × (Term Weeks + Holiday Weeks) ÷ 52.143 — following ACAS guidance for term-time workers
  • Holiday entitlement: Based on the statutory 5.6 weeks (28 days for full-time) as defined by the Working Time Regulations 1998
  • Tax calculations: Use HMRC 2025/26 rates — £12,570 personal allowance, 20% basic rate, 40% higher rate
  • National Insurance: Current 2025/26 employee NI rates from HMRC
Important disclaimer: Our calculators provide estimates for guidance only. They do not constitute financial, tax, or legal advice. Always verify calculations with your employer, HR department, or a qualified professional. Individual circumstances, contractual terms, and employer rounding methods may affect actual pay.

Editorial Standards

All content on ProRataCalculator follows strict editorial standards:

  • Accuracy: Calculations are verified against official HMRC rates and ACAS guidance
  • Currency: Content is reviewed and updated at the start of each tax year (April)
  • Sources: We cite authoritative sources including GOV.UK, ACAS, and ONS
  • Independence: We are not affiliated with any employer, payroll provider, or government body
  • Privacy: All calculations run locally in your browser — we never see or store your salary data

About Our Team

ProRataCalculator.uk is built and maintained by a small team of UK-based developers and employment content specialists. Our team has experience in:

  • UK payroll systems and employment law
  • HR and people management across education, NHS, and private sectors
  • Web development and accessibility standards
  • Financial content writing and fact-checking

We created this site because we saw how confusing pro rata calculations can be — especially for term-time workers, part-time teachers, and people transitioning between full-time and part-time roles. Our goal is to make these calculations simple, transparent, and free for everyone.

Contact Us

We welcome feedback, corrections, and feature requests. Get in touch at [email protected] or visit our contact page.