The real cost of
life's biggest decisions
15 free calculators built on ONS, GOV.UK, and HMRC data — plus a free AI advisor that explains your results and gives you a personalised action plan. No sign-up, no cost, ever.
Every calculator now has a free AI advisor built in
After you enter your numbers, ask the AI to explain what they mean — in plain English, with a specific action plan for your situation. Zero cost to you, ever.
Calculators
Pick your life event
Each tool covers a situation where the real cost surprises nearly everyone.
Remote Work True Cost Calculator
Commute savings, home office costs, meals, clothing — see your real annual net.
Salary Negotiation Calculator
See the lifetime earnings impact of negotiating and compare to BLS market benchmarks by field.
Debt Payoff Calculator
Avalanche vs. snowball comparison with your real debts — total interest saved and months to debt-free.
Emergency Fund Planner
Personalized target based on job stability, income type, and health situation — with savings plan.
Compound Interest Calculator
What a starting amount and monthly contributions grow to — split into what you paid in and what the market added.
FIRE Calculator
FIRE number, years to financial independence, Social Security impact, and portfolio projection.
Rent vs. Buy Calculator
True 5 & 10-year comparison with opportunity cost, appreciation, break-even timeline, and net wealth.
Wedding Cost Calculator
Itemized budget estimate by guest count, region, and style — with real data from 12,000+ couples.
Having a Baby True Cost Planner
State-specific year-one estimate: childcare, medical, gear, and parental leave lost wages.
Pet Cost Calculator
Year-one setup, annual recurring costs, and lifetime total — including the vet bills most people miss.
Car True Cost of Ownership
True 5-year cost: depreciation, insurance, fuel, maintenance, and financing. New vs. used vs. EV.
Home Buying True Cost Calculator
Closing costs, PMI, property taxes, HOA, insurance, and maintenance — the complete year-one picture.
College True Cost Calculator
Tuition, room & board, loan interest, and opportunity cost — the real 4-year total.
Chronic Illness Annual Cost Calculator
Beyond copays — medications, lost work, and lifestyle changes. The true annual burden.
Aging Parent Care Financial Planner
In-home care, assisted living, memory care — and the career impact on the family caregiver.
Navigate by life stage
Find tools for where you are in life
Why DecisionsCalc
Built differently
Real data sources
Every default value cites ONS, GOV.UK, and HMRC, or peer-reviewed research — not a "reasonable estimate" from thin air.
100% private
Everything runs in your browser. We never see your numbers. No account, no tracking of your inputs, ever.
Ready in 2 minutes
Pre-loaded with national averages. Change only what applies to you. Results update instantly as you type.
Free AI analysis
Every calculator includes a free AI advisor — enter your numbers, click Analyse, and get a plain-English explanation plus 3 personalised action steps.
From the guide
Recent financial guides
First-Time Buyer Stamp Duty Relief: What You Actually Pay
First-time buyer SDLT in England and NI: nothing to £300,000, 5% to £500,000, nothing above it. Who qualifies, the cliff edge, Scotland and Wales.
Stamp Duty Surcharge Refund: Reclaiming After You Sell
Paid the 5% additional-property surcharge before selling your old home? Reclaim it in full — the three-year rule, the claim deadline, and how to apply.
Capital Gains Tax When You Sell a UK Property
CGT on a UK property sale in 2026/27: the 18% and 24% rates, the £3,000 allowance, the 60-day deadline, and what Private Residence Relief covers.
The Lifetime ISA, and the Two Traps In It
How the Lifetime ISA works in 2026/27: the £4,000 limit, the 25% bonus, the £450,000 cap frozen since 2017, and the exit charge that costs more than the bonus.
The Cost of Raising a Child in the UK
What raising a child to 18 costs in the UK — the CPAG figures, why a lone parent pays more, and what Child Benefit and funded childcare take off the total.
How Much Can You Borrow? UK Mortgage Affordability in 2026
The 4.5× salary rule is widely misunderstood — it caps lenders, not you. How income multiples.
Renting vs Buying in the UK (2026): The Real 5-Year Numbers
The honest UK rent-vs-buy comparison — deposit, stamp duty, mortgage interest and maintenance against rent and the opportunity cost of your deposit.
Wales LTT Higher Rates 2026: Second Homes & Buy-to-Let
The higher residential rates of Land Transaction Tax for additional properties in Wales — the 5%-17% bands from 11 December 2024.
Scotland ADS 2026: the 8% Second-Home Surcharge
The Additional Dwelling Supplement on Scottish second homes and buy-to-let: 8% of the whole price, the £40,000 threshold, the 18-month repayment rule.
The Cost of Selling a House in the UK (2026): Full Breakdown
What it really costs to sell a UK home — estate agent fees (~1.42% inc VAT), conveyancing, EPC, removals, mortgage exit fees and CGT on second homes.
UK AVC Pension Top-Ups 2026/27: Cost and Tax Relief
What Additional Voluntary Contributions are, the £60,000 annual allowance, how tax relief makes £100 in your pension cost £80/£60/£55 by tax band.
UK Stamp Duty Rates by Year (2014-2026)
A clear history of UK SDLT: the 2014 slice reform, the 2016 additional-property surcharge, the 2020-21 holiday, the 2022 threshold rise.
Free calculators. Free AI. Free PDF checklists.
Enter your numbers, get your real costs, ask the AI what they mean — and download a personalised checklist PDF. All free, always.