Make Better Energy Decisions —
Solar, EV, Heat Pumps & Home Efficiency
Free, professional-grade calculators for the numbers that decide whether solar pays back, whether a heat pump beats gas, and what your EV actually costs to run. Every formula documented. Every assumption editable.
Quick lookup — energy questions, calculators or unit conversions
One place to answer every energy question that hits your household.
Every calculator links to the next. Solar payback references your electricity price, which flows into heat-pump savings, which feeds your carbon footprint. It's not a set of loose tools — it's an integrated energy planning platform.
Guided Decision Journeys
3 workflows · Step-by-stepAnswer one big question — should I install solar?, switch to a heat pump?, go electric? — through an ordered sequence of calculators and guides. Each step feeds the next, so you finish with a defensible decision, not a stack of loose numbers.
Journey
Should I install solar on my home?
A five-step path from "how much roof do I have?" to "what's my 25-year return?" — using the same calculators an installer would use, but with editable assumptions.
- 1Measure your roof
- 2Estimate annual output
- 3Size battery storage
- 4Calculate solar payback
- + 1 more steps
Journey
Should I replace my boiler with a heat pump?
From understanding heat demand to comparing lifetime running cost against your current boiler — six steps that translate manufacturer datasheets into your actual bill.
- 1Understand heat demand
- 2Estimate seasonal efficiency
- 3Compare against your boiler
- 4Calculate payback
- + 2 more steps
Journey
Should my next car be electric?
Six steps from "what does my driving look like?" to "what will an EV cost me per year?" — turning manufacturer marketing into numbers you can trust.
- 1Map annual mileage
- 2Size your home charger
- 3Calculate charging cost
- 4Compare vs petrol/diesel
- + 2 more steps
Energy Categories
5 topic hubs · Deep guides + live calculatorsPurpose-built hubs covering the whole energy transition — from generation to consumption to emissions. Each hub bundles a flagship calculator, supporting tools and long-form guides.
Solar Energy
Plan, size and understand a solar installation — from panel output to payback and battery storage.
Heat Pumps
Understand COP, SCOP and running cost — and see when a heat pump beats gas, oil or direct electric heating.
Electric Vehicles
Charging cost, range and total-cost-of-ownership math — from home charger sizing to petrol comparison.
Home Energy
Understand your electricity bill, size home storage, and cut standby consumption — the everyday side of the energy transition.
Carbon Footprint
Translate kilowatt-hours, kilometres, kilograms and litres into CO₂ — with emission factors you can verify.
Flagship Energy Calculators
5 calculators · Payback, savings, CO₂Each calculator goes beyond simple arithmetic — reporting annual savings, CO₂ reduction, payback timeline and energy independence indicators so you can compare investments like an analyst, not a shopper.
Solar Energy
Solar Payback Calculator
Project year-1 savings, simple payback, 25-year lifetime return, LCOE and CO₂ avoided — with editable yield, self-consumption and price inflation.
Open calculatorHeat Pumps
Heat Pump Savings Calculator
Compare annual running cost, payback and CO₂ reduction versus your current gas, oil, LPG or electric heating.
Open calculatorElectric Vehicles
EV Charging Cost Calculator
Cost per session, per 100 km, per year — plus savings vs petrol and CO₂ avoided, with editable home/public tariff split.
Open calculatorHome Energy
Home Energy Audit
Appliance-by-appliance annual kWh, running cost, CO₂ and share of bill. Surfaces standby losses and quick wins automatically.
Open calculatorCarbon Footprint
Carbon Footprint Calculator
Full personal CO₂ audit across electricity, heating, driving, flights, diet and goods — with country-specific grid factors and a 1.5 °C pathway benchmark.
Open calculatorFeatured Energy Guides
All Guides
How to Calculate Solar Panel Output and Savings
Going solar? Understanding how to calculate solar panel output is crucial for sizing your system correctly and estimating your savings. This guide covers everything from basic calculations to real-world factors affecting production.
Heat Pump Efficiency Guide: Understanding COP and SCOP
Heat pumps are revolutionizing home heating with efficiencies that seem impossible—delivering 3-5 units of heat for every unit of electricity used. This guide explains how heat pump efficiency works and helps you calculate potential savings.
How to Calculate EV Charging Time and Cost
Understanding EV charging is essential for electric vehicle owners. This comprehensive guide explains how to calculate charging time, estimate costs, and compare different charging levels to optimize your EV experience.
How to Calculate Your Carbon Footprint
Your carbon footprint is the total amount of greenhouse gases you produce. Understanding and calculating it is the first step to reducing your environmental impact. This guide breaks down the major emission sources and how to measure them.
Home Battery Storage: Complete Guide to Energy Independence
Home battery storage is revolutionizing how households manage energy. By storing excess solar power or cheap off-peak electricity, batteries provide backup power, reduce bills, and move us toward true energy independence. This comprehensive guide covers everything from capacity calculations to real-world savings.
How to Calculate CO₂ Emissions from Electricity
Understanding how much CO₂ your electricity use produces is essential for reducing your carbon footprint. However, the answer varies dramatically depending on where you live and how your electricity is generated. This guide explains how to calculate your electricity emissions.
Engineering & Energy Unit Conversions
Need a quick unit conversion while sizing a solar system, reading an EV spec sheet, or planning a heat pump install? These are the conversions that come up most in energy planning.
kWh ↔ MJ
Exact 3.6 factor — energy reporting and datasheets
kWh ↔ BTU
Heating output on US and EU spec sheets
Therms ↔ kWh
Gas bill vs heat pump electricity cost
Watts ↔ Amps
Requires voltage — circuit and breaker sizing
mAh ↔ Wh
Requires cell voltage — airline battery limits
Ah ↔ Wh
Battery bank capacity at 12 V or 48 V
kW ↔ hp
EV motor output vs engine ratings
kWh ↔ MWh
Scaling from household to utility figures
Watts ↔ BTU/h
Heat pump and air conditioner capacity
Your Calculators
General Unit Converters
View AllBeyond energy, we maintain 78+ professional-grade conversion tools for length, weight, temperature, volume, cooking, data storage and more — for when you need a reliable everyday converter.
Length
12Convert between length units
Weight
8Convert between weight units
Temperature
6Convert between temperature scales
Volume
6Convert between volume units
Area
6Convert between area units
Speed
6Convert between speed units
Time
8Convert between time units
Data Storage
14Convert between digital storage units
Medical
6Convert pharmaceutical and medical units
Cooking
6Convert kitchen and recipe measurements
Educational Resources
All Articles
Data Storage Units: MB, GB, TB Explained
Learn about digital storage from bytes to petabytes and how to convert between them.
How to Convert Celsius to Fahrenheit
Master temperature conversion with our simple formulas and examples.
Kitchen Measurement Conversions
Essential cooking measurement conversions for recipes from around the world.
Common Energy & Conversion Questions
Quick answers to the questions homeowners ask most when planning solar, heat pumps, EVs and home efficiency upgrades.
Why an Energy Intelligence Platform?
The energy transition is fundamentally a numbers problem. Whether solar panels pay back in eight or fourteen years, whether a heat pump beats your gas boiler, whether an EV actually costs less to run than your current car — every one of these questions has a defensible answer that depends on a handful of variables you can measure or look up. SnapUnitConverter exists to make that math accessible without the marketing spin that installer quotes and manufacturer brochures tend to carry.
Each calculator on this platform is built around three commitments: every formula is documented, every assumption is editable, and every result surfaces payback, running cost and CO₂ together — not as three separate tools, but as one integrated view. That's what we mean by "energy intelligence": treating the household energy system as a single portfolio of investments rather than a series of isolated purchases.
The Energy Decision Center approach
Most energy websites give you a single calculator and end the conversation there. Solar payback is calculated in isolation from your electricity price. Heat pump savings ignore what your solar array might contribute. EV charging cost forgets that a home battery could shift the load to your cheapest tariff. SnapUnitConverter's Energy Decision Center connects those threads — every calculator's output feeds forward as an input to the next.
Start with the Solar Payback Calculator to size a rooftop system. Feed the resulting kWh generation into the Home Energy Audit to see what portion of your consumption it covers. Use the Heat Pump Savings Calculator to check whether electrifying your heating is worth the capital, given your new electricity mix. Close the loop with the Carbon Footprint Calculator to see the total household impact. Four numbers, one integrated decision.
Professional-grade tools for householders
The calculators here use the same physical models an engineer would use — panel degradation curves, SCOP-weighted seasonal efficiency, DEFRA transport emission factors, IEA grid intensity data — but expose them behind interfaces designed for someone comparing installer quotes, not writing a thesis. If you want to know the assumption behind a number, click through: the formula is always shown, the source is always cited.
Unit conversion, kept where it belongs
We still maintain 78+ everyday unit converters — length, weight, temperature, volume, cooking, data — because they remain useful supporting tools for anyone doing engineering, construction, cooking or scientific work. They are calibrated, offline-capable, and free. But they are companions to the platform, not the identity: SnapUnitConverter is where you go to make an energy decision, and the unit converters are there for when the math needs them.