mmBtu-->Nm3

1. MMBTU to BTU: multiply by 1,000,000
2. BTU to MJ: multiply by 0.00105587
3. MJ to Nm³: divide by 42 (your figure).

I believe there are a few errors in what you wrote.

2. BTU to MJ: divided by 0.001055, not multiply. 1 BTU = 1,055.055 J = 0.001055055 MJ.

3. How is this possible? (1 J = 1 Nm so 1 MJ = 1,000,000 Nm) You would need to multiply by m² to get Nm³.

1 BTU ≈ 0.001055 MJ, so 2 BTU ≈ 2 x 0.001055 MJ = 0.00211 MJ, yes? That looks like multiplication to me .

Yes, i agree. Too early here.

for energy,power or any units conversion,look here http://www.convertworld.com/en/energy/

or here http://www.unitconversion.org/unit_converter/power.html

I don't think it's valid to convert to Nm³ (assuming you mean cubic meter).

THB 325/mmBTU is the price per energy of natural gas.

• mmbtu = 1 million BTU = 10 therms
• Therm = 100,000 BTU
• 1 BTU = 1,055.06 J = 1,055.06 Nm

Nm³ is a commonly-used measure of volume¹ (= 1 cubic meter at NTP), and has nothing to do with Newton-meters.

Edit: [1] - or rather the quantity of a gas.

So Nm³ is only a measure of volume at NTP? Am I correct that NTP is normal temperature and pressure? If so....then that's confusing (at least to an engineer not in that field).

Personally, I dislike the use of unit which are industry unique...even mmBTU threw me off until I looked it up and I still haven't come across Nm³ as cubic meters at NTP. It may make sense to those in the industry...but why couldn't they have used MBTU and m³ (NTP) or m³ @ NTP ... something less likely to get misinterpreted?

Good questions, all.

Nm³ also crops up sometimes when talking about compressors & pneumatics etc. I don't like it either. Just to make things worse, there's also a Sm³ (standard cubic meter).

I am quite comfortable with both SI and MKS and understand why some industries still use MKS, although, I am much more at home with MKS having been raised in the US.

One of the most confusing things for most people (including engineers) to get their mind wrapped around is the conversion factor gc (32.174 lbm-ft / lbf-sec²). As a result, we have to distinguish between pounds force (lbf) and pounds mass (lbm). The SI system of units nicely avoids this confusion.

About 15 years ago, I was working with a Japanese company on a servo actuator design. They presented me with data and information using kgf as one of the units. I asked them what that was...it was kilogram force. AARRRRRGHHHHH I just about had an aneurysm!!!!! Why introduce that level of confusion again? Call it Newtons or dynes....even pounds force....but don't create a new unit!!!!