Work it out.
Calculators
Plant spacing and plant requirement
Geometri / arealregning
Timber volume of standing trees
Skovbrugsformel: V = g x h x f
Firewood: stacked cubic metres to solid wood
Råtræ-opmåling (fastmassetal)
Thinning percentage
Forholdsregning (tyndingsstyrke)
Calorific value: energy content of firewood
Brændeværditabel (brændeforhandleres normtal, fx Roskilde Brændesalg / Træ.dk)
Relascope measurement: basal area per hectare
Bitterlich-metoden (vinkeltælling med relaskop)
Standing timber volume per hectare
Skovbrugsformel: V = G x H x f (bevoksningsniveau)
Safety distance when felling
Skovsikkerhedsregel (fra den tidligere At-vejledning D.2.8 om fældnings- og skovningsarbejde, ophævet 15-12-2025)
Uncultivated buffer strip along watercourses
Vandløbsloven § 69 (2 meter dyrkningsfri bræmme)
Tønder land to hectares
Historisk arealenhed (1 td. land = 5.516,24 m²)
Chainsaw chain speed
EN ISO 11393-2:2019, tidligere DS/EN 381-5 (skærebeskyttelsesklasser 1-3, kædehastighed 20-28 m/s)
Carbon and CO2 in the wood mass
IPCC-standardfaktorer (kulstoffraktion 0,5; CO2:C-molvægtforhold 44:12) + trædensitet
Spray liquid: dosing and tank mixing
Miljøstyrelsens etiketkrav (dosis jf. det konkrete produkts godkendte brugsanvisning)
Establishment rate after planting
Forholdsregning (kulturkontrol/efterbedring)
Sustainable felling: harvest vs. growth
Forholdsregning — bæredygtighedsprincip (hugst ≤ tilvækst, jf. skovcertificering FSC/PEFC)
RTA: relative tree spacing and felling intensity
RTA method (relative tree distance = tree distance as % of overhang, Hart-Becking)
Cubing stems by mid-diameter
Huber formula with mid-diameter without bark (Raw Timber Handbook Danish Forest Society 2008)
Lowering: load on rope and anchor point
Forces over a block: F = 2 · T · cos(θ/2); 10:1 safety factor for rigging rope (New Zealand Arboriculture Best Practice Guideline)
Felling plan for roe deer
DCE memo 2025/23 (0.82 calf per 3+-year-old hind, 0.57 per 2-year-old, non-hunting mortality 2%) and Wildlife Management Council's distribution 25/25/50
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.