Work it out.
Calculators
CPR rate and cycles (30:2)
Dansk Førstehjælpsråd / ERC 2025
Time without resuscitation - your own rate
Brugerindtastet sats
Retrieval time for a defibrillator (AED)
TrygFonden / Dansk Råd for Genoplivning — Hjertesikker Zone
Distance to fire-extinguishing equipment during hot work
DBI Brandteknisk Vejledning 10 (varmt arbejde) — maks. 25 m til slukningsudstyr
Number of fire extinguishers by floor area
Vejledende branchepraksis (fx Dansk Brandteknik) — ikke et fast lovkrav-tal
Coverage: extinguishing agent vs. your fire classes
DS/EN 2 (brandklasser) og DS/EN 3 (bærbare ildslukkere)
Escape route distance and walking time to the nearest exit
BR18 — vejledning til kap. 5 Brand (præ-accepterede løsninger)
Minimum number of smoke alarms in the home
BR18 — vejledning om røgalarmer i boliger
Number of first aiders from your own ratio
Arbejdstilsynet — APV-baseret vurdering (intet fast lovkrav-tal)
VEU allowance and course finances 2026
uvm.dk / borger.dk — VEU-godtgørelse og deltagerbetaling 2026
Range and discharge time for a powder extinguisher
Fabrikant-datablade for 6 kg ABC-pulverslukker (DS/EN 3)
Status of your refresher course
Dansk Førstehjælpsråd — anbefalet genopfriskningsinterval
Child CPR: cycle and rate (30:2 for lay rescuers, 15:2 for healthcare professionals)
Dansk Førstehjælpsråd 2026 · ERC Guidelines 2025
Fire blanket area and effective coverage
Geometri — ingen fast DS/EN-norm for dækningsareal (kun standard tæppestørrelser findes)
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.