⚖️ Convertisseur de Masse

Weight units are the least standardized thing in daily life - the US says pounds, the UK says stone, and then there are the two tons. If your workflow involves describing a subject's weight in a prompt, pricing by mass, or any other quantity that needs a conversion you don't want to do in your head, ⚖️ Convertisseur de Masse is the CalculatorPro node for it. Three inputs, two outputs, no surprises.

The units

from_unit and to_unit each offer 11 choices, all with their factor stored relative to the gram: gram, kilogram, milligram, microgram, metric tonne, plus the imperial set - pound (lb), ounce (oz), grain, stone, and both the UK long ton and US short ton. That last one is the detail that makes this node better than your phone's converter: a long ton is 1,016,050 g and a short ton is 907,185 g, and this pack keeps them as separate named entries so you never convert a US "ton" into a UK one by accident.

Mechanically it's identical to the pack's other converters: normalize your value (FLOAT) into grams, divide by the target's gram factor, done. Pure multiplication against hardcoded constants - no data files, no web lookups.

What comes out

You get result (FLOAT) with the bare converted number and output_str (STRING) with the formatted line, e.g. 1 g = 0.00220462 lb. The string output is the one to wire into a prompt assembler if you're doing the "subject weighs X pounds" style of dynamic prompt; result is the one to feed into further math if you're chaining conversions or computing something with the weight.

Honestly, this node and its siblings solve a niche problem - most ComfyUI graphs never touch units at all. But when you need it, you need it inside the graph, because the alternative is a static text prompt that doesn't update when you change the input value. That's the whole argument for the suite: one FLOAT widget as your source of truth, and the converted string updates every run.

The gotchas

The two "tonne UK/US" entries are the trap to respect - they are not the same as the metric tonne (the labels are distinct in the dropdown, but it's easy to grab the wrong one). The dropdowns are in French, consistent with the rest of the pack. And there's no rounding on result, so feed it onward with that in mind.

Install

Standard CalculatorPro install - one clone, eight nodes:

cd ComfyUI/custom_nodes
git clone https://github.com/orion4d/Calculator_Pro

restart ComfyUI, or search "Calculator_Pro" in ComfyUI Manager. No requirements.txt, no models, nothing to configure. The whole pack is a single pure-Python file, which is why installing it is a 30-second operation that can't break your other nodes.