Tools / Prices as of 21 October 2026
Coal analysis converter
Lab reports give coal figures on different bases, which makes two reports hard to compare. Enter the figures from yours and see them as received, air dried, dry and dry ash free, side by side.
1 Which basis is your report on?
Look for ADB, AD, ARB, AR, DB or 'dry' next to the figures.
2 Moisture figures
Total moisture (TM), as received
Inherent moisture (IM), air dried
Total moisture is always as received; inherent moisture is always air dried.
3 Figures from the report
Gross calorific value
Ash
Volatile matter
Total sulphur
Add hydrogen for net calorific value
Hydrogen, on the same basis as the report
From an ultimate analysis. Balochistan coal is usually about 4 to 5% air dried.
Gross calorific value, as received
6,038 kcal/kg
That is 25.3 MJ/kg or 10,868 BTU/lb.
| Parameter | ARB | ADB | DB | DAF |
|---|---|---|---|---|
| Moisture, % | 8.0 | 4.0 | 0.0 | 0.0 |
| Ash, % | 10.5 | 11.0 | 11.5 | n/a |
| Volatile matter, % | 36.4 | 38.0 | 39.6 | 44.7 |
| Fixed carbon, % | 45.0 | 47.0 | 49.0 | 55.3 |
| Sulphur, % | 4.3 | 4.5 | 4.7 | 5.3 |
| Gross calorific value, kcal/kg | 6,038 | 6,300 | 6,563 | 7,412 |
ARB as received · ADB air dried · DB dry · DAF dry, ash free.
Ask for our lab analysisNo black box.
As received includes all the moisture in the coal as delivered. Air dried leaves only the inherent moisture. Dry removes all moisture, and dry ash free removes the ash too, leaving just the burnable part.
Each figure is first put on the air dried basis, then scaled by the moisture (and ash) to the others, using the standard conversions in ISO 1170 and ASTM D3180. Net calorific value takes off the heat carried away as water vapour.
Results are estimates for planning. Coal prices are indicative and confirmed when you contact us.
What people ask.
What is the difference between ADB and ARB?
ADB (air dried basis) is the coal after it has dried in air in the lab, with only its inherent moisture. ARB (as received) is the coal as delivered, with all its moisture. ARB figures are lower and are what you actually burn.
How do I convert GCV from ADB to ARB?
Multiply the ADB value by (100 minus total moisture) divided by (100 minus inherent moisture). For example, 6,300 kcal/kg ADB with 8% TM and 4% IM is about 6,040 kcal/kg as received.
What is the difference between GCV and NCV?
Gross calorific value counts the heat in the water vapour formed when coal burns; net calorific value does not, because that heat escapes up the chimney. NCV is lower, usually by 250 to 350 kcal/kg for this coal.
How do I convert kcal/kg to MJ/kg?
Multiply by 0.0041868. So 6,000 kcal/kg is about 25.1 MJ/kg.
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