Quick answers to
everyday money math

Why you can trust the numbers

Personal-finance and health calculators are only useful if you can trust the answer. Every tool on CalcOrchard follows four rules: use the standard formula from a primary source (HMRC, the IRS, a finance textbook, a peer-reviewed medical study), show the working in plain English, keep your data in your browser, and be explicit about what the tool doesn't cover.

UK tax calculators use the current 2024/25 rates and thresholds and are refreshed after each Budget. US tax calculators use the current IRS-published figures. Every new calculator is spot-checked against at least two independent published worked examples before it goes live. If we change how a tool works, we say so.

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UK contractors, landlords, and self-employed

Recent additions focus on situations where the "right" tax outcome is genuinely non-obvious — the kind of decision where a good calculator saves you thousands of pounds a year.

• £100k Trap Escape Toolkit (£19 Excel) — a 6-sheet interactive workbook that runs the salary-sacrifice, bonus-timing and Personal Allowance recovery maths on your numbers. Our first paid product; companion to the free playbook below.
• The £100k Trap Escape Playbook (free PDF) — a downloadable 12-page playbook with 12 legal moves to beat the 60% marginal rate that hits UK earners between £100k and £125,140. Worked example, 5-minute self-audit checklist, no signup.
• Inside vs Outside IR35 — the full deemed-salary umbrella calculation on one side and the salary-plus-dividends limited-company optimisation on the other. See what the difference is at your day rate.
• ISA vs GIA — long-run tax savings — projects the same portfolio in a Stocks & Shares ISA and a General Investment Account over 10–30 years. Shows the annual dividend-tax drag plus the terminal CGT hit on the unwrapped side — usually £20k–£40k of tax avoided over 20 years at a modest £500/month contribution.
• SIPP tax relief — the four layers of relief: 25% auto uplift, higher-rate top-up via Self Assessment, the £100k Personal Allowance restoration bonus that gives 60% effective relief, and Employee NI savings if you use salary sacrifice.
• Lifetime ISA (LISA) — models the £1,000/year government bonus, growth to a first home or age 60, and — critically — the 25% early-withdrawal penalty that turns a LISA into a net loss if you change plans. Completes the UK wrappers cluster (ISA + SIPP + LISA).
• Hourly rate → annual salary tables (UK) — every popular UK hourly rate from £10 to £100/hour converted to gross annual salary and take-home pay. Includes 35/37.5/40-hour week comparison and full 2024/25 Income Tax + NI breakdown per rate.
• Salary take-home tables (£20k–£150k) — precomputed after-tax take-home for every £5k salary bracket in the UK, 2024/25 rates. Each page shows the Income Tax + NI breakdown, pension comparison at 0/5/10%, marginal rate, and a jump to neighbouring salaries. Handy if you're negotiating a specific number.
• The £100k Tax Trap: How the 60% Rate Actually Works — a deep guide to the tapered Personal Allowance that creates a 62% marginal rate on the £100k–£125,140 slice. Includes worked examples, the four legitimate escape routes (salary sacrifice, SIPP top-ups, Gift Aid, bonus timing), and when it's not worth escaping.
• Total Compensation Calculator — compares two UK job offers on their true value, not just base salary. Prices in employer pension contributions, RSUs / share options with a confidence discount, salary sacrifice tax savings, private medical BiK and holiday days. Reveals the £5k–£30k of value hidden behind the headline number.
• Umbrella take-home — reverse-engineers the gross salary an umbrella can pay from your assignment rate, factoring in employer NI, apprenticeship levy, salary sacrifice pension, and every student loan plan.
• Company car BIK tax — 2024/25 BIK percentages for every fuel type, from 2% for pure electric up to 37% for high-emission diesel. Shows the annual tax bill and the fuel benefit trap.
• Section 24 landlord tax — models the notorious 20% mortgage-interest credit that replaced full deduction. Higher-rate landlords can end up with an effective tax rate above 50% on their true economic profit; the tool shows exactly how big the gap is between personal ownership and a limited company.
• Rental yield & cash-on-cash — the three yield numbers that actually matter: gross, net after real costs, and cash-on-cash ROI including mortgage leverage. Companion to the landlord tax calculator.
• CIS tax deduction — for subcontractors under the Construction Industry Scheme. Per-invoice deduction plus year-end Self Assessment reconciliation showing your rebate or balance due.
• Self-employed tax — Class 4 NI (plus the Class 2 quirk), the trading allowance, the payment-on-account schedule, and how partial-year earnings interact with the personal allowance.
• UK take-home pay — including student loan plans 1/2/4/5 and postgraduate, and the personal-allowance taper above £100k that catches out higher earners.

Also new: a growing library of educational articles at /blog/ covering things like how compound interest actually works, the difference between markup and margin, and how to legally minimise your UK tax bill.

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