Work it out.
Calculators
Electricity consumption & power cost
Ren enhedsomregning (kWh = W × timer ÷ 1000)
Energy saving from replacement
Ren matematik (besparelse = før − efter; tilbagebetaling = pris ÷ årlig besparelse)
CO2 footprint of energy consumption
Ren multiplikation — emissionsfaktor indtastes fra officiel kilde
Waste recycling rate
Ren procentregning (sorteret ÷ total × 100)
CO2 tax on the company's emissions
CO2-afgiftsloven + grøn skattereform for industri (2022-aftalen) — sats og godtgørelsesprocent skal tjekkes for aktuelt år
Heat pump saving (SCOP)
SCOP-metoden (Energistyrelsen/sparenergi.dk) — egne priser og forbrug
Annual output of a solar PV system
Branche-tommelfingerregel for dansk solindstråling (budgetenergi.dk/greenmatch.dk/1komma5.com, ca. 800-1.000 kWh/kWp/år)
CO2 emissions from transport
Nyregistrerede bilers gennemsnitlige CO2-udledning (Danmarks Statistik/Miljøstyrelsens bilstatistik, 2024-tal) — ændres årligt, tjek aktuelt tal
Water saving with aerator/eco shower head
Ren forholdsregning — flowtal fra egen måling eller produktdatablad
Insulation savings (degree-day method)
Graddagemetoden (Teknologisk Institut/SBi) — graddage varierer år for år, tjek aktuelt tal
Idling — fuel waste and CO2
Forbrændingens CO2-faktor for diesel/benzin (danske standardfaktorer, jf. Energistyrelsen/Energinet) — eget tomgangsforbrug indtastes
Savings from an improved energy label
Ren forholdsregning ud fra energimærkets kWh/m²/år-tal (Energistyrelsens energimærkningsordning)
CO2 offsetting by tree planting
Gennemsnitligt CO2-optag for et træ i vækst (EcoTree/Miljøbevidst — varierer med art, alder og vækstforhold)
Electric car vs. petrol/diesel car — running cost per km
Ren forholdsregning — egne forbrugstal fra deklaration eller køretøjets computer
Tools that work in all subjects
Whatever your programme is called, these tools calculate the same — Pythagoras, area, percentages and units are not tied to one trade.
- Pythagorasa² + b² = c²Find the missing side, set out a right angle, check whether a room is square, and find the space diagonal.
- Area and perimeterm²Rectangle, triangle, trapezium, circle and composite shapes — area and perimeter.
- Volume and surface aream³ · lBox, cylinder, cone, sphere, pyramid, prism, pipe and frustum — also in litres.
- Percent%Percentage of, how many per cent, percentage change, discount and VAT.
- Scale and ratios1 : 50From drawing to reality, area and volume to scale, the rule of three and dividing in a ratio.
- Unit convertermm ↔ mFrom mm to km, Pa to bar and kB to GB — with the unit staircase.
- Time calculations and the clockt : minTime between two clock times, add time, and 1.75 h = 1 h 45 min for the timesheet.
- Slope and fall% · ° · 1:xFall from level to level, in per cent, per mille, degrees and mm per metre — and the height difference.
- Material consumption including wastem² + %Boards, paint, battens at c/c spacing and packs — for a composite surface or a whole room, with waste.