Wiki

How UK savings interest tax works, including the Personal Savings Allowance, starting rate for savings, and band allocation for 2025/26.

How UK take-home pay is calculated from gross salary — income tax, NI, student loans, pension, salary sacrifice, BIK, Gift Aid, and Child Benefit.

How buy-to-let rental profits are calculated, including Section 24 tax impact, mortgage costs, yields, and lender stress tests.

A guided 5-step journey to understand how much you can afford as a first-time buyer, from salary to monthly costs and full affordability verdict.

How long it takes to save a mortgage deposit, with compound interest, monthly contributions, and government schemes like Lifetime ISA.

How UK lenders estimate how much you can borrow using income multiples, existing commitments, and stress testing.

How a mortgage amortization schedule breaks down each payment into principal and interest, with the standard formula and a worked example.

How mortgage overpayments save interest, the 10% annual limit, early repayment charges, and the overpay-vs-invest comparison.

How UK monthly mortgage payments are calculated for repayment and interest-only mortgages, with the amortization formula, arrangement fees, and worked examples.

How UK property flip profit is calculated, including stamp duty, bridging finance, renovation costs, and tax treatment (CGT vs income tax).

How to calculate your remaining mortgage balance after a given number of years, using the standard balance formula with principal, interest, and equity.

How to work out how much rent you can afford in the UK, using the 30% rule, landlord referencing, and budget-based approaches.

How rental yield is calculated for UK buy-to-let property, including gross yield, net yield, and return on investment vs deposit.

How the UK shared ownership scheme works, with monthly cost breakdowns, rent on the unowned share, and comparison to renting and buying outright.

How UK Stamp Duty Land Tax (SDLT) is calculated, with band rates, first-time buyer relief, and additional property surcharge.

Complete breakdown of upfront cash needed to buy a UK property: deposit, stamp duty, solicitor fees, survey costs, mortgage fees, and moving costs.

How to compare two mortgage deals by total cost, including interest rates, arrangement fees, and fee handling — with the standard amortization formula.

How UK renovation costs are estimated for kitchens, bathrooms, loft conversions, extensions, and more — with quality and regional adjustments.

How LTV ratio is calculated, what UK lender bands mean for mortgage rates, and how to check your equity position with a reverse-lookup.

How to compare the financial outcomes of renting versus buying a home in the UK, using a capital equalization model with property growth and investment returns.

How to calculate whether remortgaging saves money — comparing monthly payments, total interest, switching costs, and break-even time.

How to calculate your FIRE number, understand safe withdrawal rates, and plan your path to financial independence using the 4% rule.

How compound interest is calculated, with formulas for lump-sum growth and regular contributions, worked examples, and compounding frequency comparison.

How ongoing fund charges (OCF) compound over time, dramatically reducing long-term investment growth. Compare low-cost index funds with actively managed funds.

How UK Individual Savings Accounts (ISAs) work, including the £20,000 annual allowance, Lifetime ISA bonus, and ISA vs GIA tax comparison.

How UK Junior ISAs work — annual allowance, tax-free growth, who can contribute, and what happens when your child turns 18.

How savings withdrawal works with inflation-adjusted drawdowns, the 4% rule, and month-by-month depletion modelling.

How to calculate your personal net worth by totalling assets and subtracting liabilities, with UK median wealth benchmarks by age.

How UK pension drawdown works: tax-free lump sum, income tax on withdrawals, pot longevity, and withdrawal rate sustainability.

How compound interest with regular contributions determines how long it takes to reach a savings target like one million pounds.

Calculate the monthly savings needed to reach a target, or find how long it takes at a fixed contribution rate.

How much emergency savings you need based on monthly essential expenses, with guidance on coverage periods for different employment situations.

How the 50/30/20 budgeting rule splits your after-tax income into needs, wants, and savings to build a simple, balanced monthly budget.

How Body Mass Index is calculated, with NHS categories, ethnic-adjusted thresholds, and limitations of BMI as a health metric.

How calorie cycling for body recomposition works, with Mifflin-St Jeor BMR, training vs rest day splits, and macro targets.

How calorie expenditure during exercise is estimated using MET values from the Compendium of Physical Activities.

How daily water intake is estimated from body weight, activity level, climate, and exercise, using EFSA guidelines and ACSM fluid replacement research.

How Fat-Free Mass Index is calculated, with sex-specific categories, height normalization, and natural muscle limits from the Kouri 1995 study.

How fitness age is estimated from VO2max using the Jackson et al. (1990) non-exercise prediction equation and Uth heart rate ratio method.

How heart rate training zones are calculated using the percentage-of-max and Karvonen methods, with Tanaka and traditional max HR formulas.

How ideal body proportions are calculated using Steve Reeves, John McCallum, and Grecian golden ratio models.

How lean body mass is estimated using the Boer, James, and Hume formulas, with worked examples and verification against published coefficients.

How four independent models — Casey Butt, Martin Berkhan, Lyle McDonald, and FFMI — estimate the genetic ceiling for muscle mass in drug-free lifters.

How one-rep max (1RM) is estimated from submaximal lifts using the Epley, Brzycki, and Lander formulas, with training percentage charts.

How daily protein needs are calculated from body weight, goal, and age using evidence-based ranges from NHS, ISSN, and sports science.

How running pace, finish time, and race predictions are calculated, with Riegel's formula for predicting race times across distances.

How walking step counts are converted to calories burned, using MET values from the Compendium of Physical Activities and stride length estimation from height.

How Wilks, Wilks-2, and DOTS powerlifting scores work — polynomial formulas, coefficients, strength levels, and percentile rankings.

How Total Daily Energy Expenditure is estimated using the Mifflin-St Jeor and Harris-Benedict BMR equations with activity multipliers.

How daily calorie targets are calculated for weight loss, muscle gain, and body recomposition using TDEE, energy balance, and macro splits.

How optimal bedtimes and wake-up times are calculated using 90-minute sleep cycles, with sleep onset latency and NHS-aligned duration recommendations.

How WHR is calculated, WHO risk thresholds for men and women, waist circumference categories, and why WHR matters for cardiovascular risk.

How protein shakes support muscle protein synthesis — leucine thresholds, BCAAs, complete vs incomplete proteins, and practical shake building.

How the cost of raising a child from birth to 18 is estimated, including childcare, food, education, housing, and government support.

How to split a restaurant bill fairly, with equal, percentage, itemised, and income-based methods, plus UK tipping etiquette.

How to calculate what car you can afford, compare PCP vs HP vs bank loan finance, and understand car depreciation in the UK.

How to calculate the true annual cost of owning and running a car in the UK, including depreciation, fuel, insurance, tax, and maintenance.

Compare the cost of driving by petrol, diesel, or electric vehicle in the UK, with formulas for fuel consumption, trip cost, and CO2 emissions.

How total monthly running costs are estimated for UK households, including energy, council tax, water, broadband, TV licence, and insurance.

Annual, monthly, and lifetime costs of owning a dog, cat, or rabbit in the UK, with breakdowns by size and care level.

How to calculate the true cost of recurring subscriptions on a monthly, annual, and daily basis, with UK pricing benchmarks.

How timezone conversions work, including UTC offsets, DST rules, and finding business hour overlap across multiple zones.

How weekly, monthly, and annual food spending is estimated by household size, diet style, and eating-out habits using ONS and Defra data.

How a dual-income household can work out whether the second salary is really worth it after childcare, tax, commuting, and work expenses.

How to calculate solar panel payback period, lifetime savings, and return on investment for UK residential installations.

How spending on a wedding delays saving for a house deposit, with itemised costs, savings timelines, and opportunity cost projections.

How the food nutrition database is built from USDA FoodData Central, with nutrient data per 100g, macro energy split, and micronutrient % daily values.

How meal nutrition totals are calculated from USDA food data, including macro/micro scaling, Atwater energy factors, and RDA percentages.

How recipe ingredients are scaled proportionally between serving sizes, with USDA nutritional data and worked examples.

How the food substitution algorithm suggests healthier ingredient swaps based on protein, calories, fiber, glycemic index, or balanced goals.

How the everycalc wiki is built: methodology documentation, source verification, and quality standards.