Calculators for your situation
A single calculator answers one question. A guide strings the right ones together — in the order you actually need them — so you see the whole picture, not just an isolated number.
A first-time buyer runs three calculators and ends up with…
£15,000
deposit needed
£2,500
stamp duty
£180,000
they can borrow
Three correct numbers — and no answer. Because the real question was never “what’s the stamp duty.” It was “can I actually afford this place?” That’s what a guide is for: it runs the calculators in the right order, the way a UK accountant or mortgage adviser would, so the figures add up to a decision instead of a pile of numbers.
Browse all guides
Twenty-five step-by-step paths through our UK calculators, each built around a situation rather than a single tool.
For First-Time Buyers
From what you can borrow to stamp duty, deposit and monthly cost — the full path onto the ladder.
View guide →For Contractors
Day rate, IR35, salary vs dividend and VAT — work out what you really keep as a contractor.
View guide →For Landlords
Rental yield, income tax, the stamp duty surcharge and CGT — the numbers behind a buy-to-let.
View guide →For Side-Hustlers
The £1,000 trading allowance, when to tell HMRC, and the tax on earnings alongside a day job.
View guide →For Early Retirement (FIRE)
Your FIRE number, drawdown, annuity vs drawdown and the pots to get you there sooner.
View guide →For Ltd Company Directors
Sole trader vs ltd, profit, how to pay yourself, and the director’s loan and pension angles.
View guide →For Getting Out of Debt
Avalanche vs snowball, credit card payoff and your debt-free date — a clear route out.
View guide →For High Earners
The £100k trap, the 60% band, allowance taper and salary sacrifice — taming a big tax bill.
View guide →For First-Time Investors
Compound growth, ISA vs SIPP and how much to invest — the basics, with the maths to back them.
View guide →For Remortgaging & Moving
Remortgage, early repayment charges, overpayments and a fresh affordability check before you move.
View guide →Overpay Mortgage vs Invest
A guaranteed return against an uncertain one — settle the classic overpay-or-invest question for your rate.
View guide →Pay Off Debt vs Save
Debt interest against savings returns — work out whether to clear what you owe or build savings first.
View guide →Sole Trader vs Limited Company
Tax, take-home and admin compared at every profit level — pick the right structure for your business.
View guide →For New Parents
Budgeting on one income, the child benefit charge and saving for your child — money for a new arrival.
View guide →For Approaching Retirement
How much pension you need, drawdown and income that lasts — the final years before you stop work.
View guide →How Much Deposit for a House?
The 5–10% rule, how your deposit shapes your rate, help schemes and the cash costs on top.
View guide →How Much Do I Need to Retire?
Benchmark lifestyles, the pension pot behind them, and the State Pension’s role in your number.
View guide →How Much Emergency Fund?
Three to six months of essentials — and how job security and outgoings size yours.
View guide →How Much Should I Save a Month?
The 50/30/20 rule, working back from your goals, and setting a figure you can keep up.
View guide →How Much to Invest for £1 Million?
The monthly figure by timeframe, and why starting early beats investing more later.
View guide →How Much Can I Borrow for a Mortgage?
Income multiples, the FCA 4.5× rule and the levers that move your limit up or down.
View guide →How Much Is Stamp Duty?
What you’ll pay by buyer type and price band — and why it’s less than most people expect.
View guide →How Much Pension Do I Need?
Minimum, moderate and comfortable — the income and the pension pot behind each.
View guide →How Much to Earn to Buy a House?
The salary behind each price band — and why couples need far less each.
View guide →How Much Tax on a Second Job?
Why it’s not a higher rate, what the BR tax code means, and how to avoid a bill.
View guide →How Calclens guides work
Pick your situation
Choose the guide that matches where you are — buying, contracting, investing, retiring.
Follow the path
Work through the calculators in order. Each step explains why it comes when it does.
See the whole picture
By the end you have every number that matters, not one figure in isolation.
About these guides
Each guide links to free Calclens calculators, sequenced the way a UK purchase, tax year or investment decision actually unfolds. Guides don’t replace the calculators — they tell you which to use, in what order, and why.
Figures and thresholds across the guides follow current HMRC, GOV.UK and FCA guidance, with the detail and sources held on each individual calculator page. See our methodology and sources.
Not financial advice. Calclens guides are for general information and link to calculators that produce estimates. For decisions about a mortgage, tax position or investment, confirm the figures with a suitably qualified professional before acting.