Free Eco Home Calculators

Savings Tracker

1 min read Last updated 20 May 2026
Quick answer A typical £8,000 upgrade saving £600 a year (£50 a month average) pays back in 13-14 years at 0% inflation, or 9-10 years at 5% energy-price inflation. Solar saves most in summer; insulation, heat pumps and new boilers save most in winter.

The Monthly Savings Tracker projects month-by-month and year-by-year savings for any eco upgrade, with seasonal variation built in. It accounts for energy-price inflation and shows when payback occurs to the nearest month.

Monthly Savings Tracker

Track projected monthly savings and cumulative returns from your eco upgrades.

Average monthly saving on energy bills. Seasonal variation is modelled automatically.

See 20 real-world examples

Each link below runs this calculator with real UK city and property inputs and publishes the exact computed savings, payback time, install cost and CO2 figures.

Browse all calculator examples →

How this calculator works

Monthly savings = base monthly saving × seasonal factor × cumulative inflation. Seasonal factors are tuned per upgrade type: solar peaks in June (1.6× the average month) and dips in December (0.3×); heating-related upgrades (heat pump, insulation, windows, boiler) peak in January (1.5×) and dip in July (0.2×); batteries are roughly flat year-round. Cumulative inflation = (1 + annual rate)^year. Payback occurs in the first month cumulative savings exceed net cost.

Sources & references

Frequently asked questions

Why does my saving change month to month?

Energy use isn't flat across the year. Heating-related savings concentrate in winter (when you actually use heating); solar PV concentrates in summer (longer days, higher sun angle). Modelling annual savings as 12 × monthly average can mislead — winter months for heating savings are 5-7× summer months.

What inflation rate should I assume?

UK gas and electricity prices have risen 6-8% real-terms annually since 2020 due to gas market volatility and decarbonisation costs. 5% is a reasonable central estimate; 3% conservative; 8% pessimistic.

Is this an actuarial projection?

No — it's a planning tool. We don't model boiler breakdowns, battery degradation, panel soiling, or interest rates if you finance the install. Use the figures as a budgeting baseline, not a financial guarantee.

How does inflation change payback?

A £600/year saving at 0% inflation pays back £8,000 in 13.3 years. At 5% inflation, payback drops to 10.5 years (savings grow each year). At 8%, just 9 years.

Tool: Monthly Savings Tracker. Last reviewed: . Figures based on Ofgem price cap, gov.uk grant guidance, and Energy Saving Trust advice. Verify scheme eligibility with your installer before commissioning work.