Why
The guide already holds, as figures checked against the legal texts, every equipment number in Europe: Denmark’s 40 joules, Finland’s 180 N, Hungary’s 222.7 N, Portugal’s 25 millimetres. They are scattered over thirty pages, in units that do not compare with each other — newtons here, pounds there, joules in Denmark — and nobody adds them up when choosing a bow.
The tool above adds them up. It does not tell you what is legal; it tells you which figures you meet. What is legal is written on each country’s page, with the article it comes from.
How it is worked out
Arrow energy is kinetic energy: half the mass times the square of the speed, with the mass in kilograms and the speed in metres per second. 450 grains at 270 fps come to just under 100 joules. The conversions used: one pound-force is 4.448 newtons, one grain is 0.0648 grams, one foot per second is 0.3048 metres per second.
Nothing here is to be taken on trust: it is the formula out of the textbook, applied to the figures in the guide.
The mechanical point
Denmark does not require a mechanical point. Of the thirteen countries read it is the only one whose text mentions such a head at all, and it mentions it in two places:
- § 5 (2) no. 1 of the Danish weapons order: for red, fallow and sika deer, a fixed point (fast spids), at least three-bladed, cutting at least 25 mm. A mechanical head does not meet that.
- § 5 (1) no. 2: for roe deer, fox, hare and goose the requirement is 40 joules and a 25 g arrow, “Dog skal anslagsenergien ved brug af pil med mekanisk spids være mindst 70 Joule” — with a mechanical point, at least 70 joules.
The order gives no reason. We have read neither the explanatory memorandum nor the public consultation, so this article cannot say what reasoning sits behind the 70 joules — only that the figure is there, and that it is 30 higher than for a fixed point.
Tick the box and the table applies exactly those two rules: the red deer row fails, and the roe deer row asks 70 joules instead of 40.
Hungary says expressly that its law does not distinguish fixed from mechanical. Finland, Slovakia, Serbia, Spain, France, Portugal and Türkiye do not raise the subject in any text we read.
Joules and newtons do not convert
The question comes up the moment you look at the table: Denmark asks for joules, Finland for newtons — how do you get from one to the other? You do not. A newton is a force, a joule is an energy; they are different quantities, like the metre and the second. There is no conversion factor between them, and the tool never turns one into the other.
That is why it asks for both. The draw weight you type is compared with the thresholds written as force — 180 N, 220 N, 222.7 N, 45 lb. The energy is worked out from the arrow’s mass and speed and compared with the thresholds written as energy — Denmark’s 40, 70 and 80 joules. The only conversions it makes are between units of the same quantity: pounds-force to newtons, grains to grams, fps to metres per second.
A physical link exists — the energy a bow stores is the area under the force-draw curve, and the arrow takes only a share of it — but it is not a number you can apply. To know the energy, you measure it: the arrow’s mass and its speed.
From the definitions alone it follows that draw weight does not determine energy: two archers who both clear Finland’s 180 N can put different energies into the animal, because the energy depends on mass and speed as well. The Danish text asks for anslagsenergi (E0), the energy as the arrow leaves — exactly the quantity the formula gives, with the speed measured at the bow.
What the tool does not do
It does not tell you that you may hunt. Equipment thresholds are the last requirement in a line that starts with the licence, the exam, the insurance and the ground’s permit. A bow that clears every row in the table is no help at all in Romania, where hunting with a bow is a criminal offence.
It does not settle how the measuring is done. Not one of the texts read says how draw weight is checked at an inspection — not Slovakia’s 220 N, not Hungary’s 222.7 N. If you go to the limit, the margin is yours, not the law’s.
It does not mistake a legal minimum for a recommendation. Denmark’s 40 joules are the legal minimum for roe deer, and the same order asks 80 for red, fallow and sika. What is appropriate for a particular animal is not written in any text we read.
It does not model every case. It does not check the number of blades — Denmark asks three on red deer and on the roe deer class, Murcia three on big game — and there is no checkbox for the blunt, allowed in Denmark on small game at 70 joules instead of 40. Species exclusions are outside it too: Denmark keeps mouflon and wild boar out of bowhunting altogether under § 4 (2), whatever energy you carry. The rows are classes of equipment, not lists of permitted species.
It does not update itself. The figures are copied from the country pages, and each of those carries the date it was checked. When a law changes, the country page changes first and this follows.