LiquidUU Conversion Ratios and Rationale

First, here are the final default conversion ratios, in the order they are presented:

  • 3 UU + 1 oil = 2 oil
  • 5 UU + 1 fuel = 2 fuel
  • 5 UU + 1 biofuel = 4 biofuel
  • 3 UU + 1 biomass = 13 biomass
  • 3 UU + 1 apple juice = 9 apple juice
  • 3 UU + 1 liquid honey = 9 liquid honey
  • 5 UU + 1 seed oil = 21 seed oil
  • 5 UU + 1 creosote oil = 31 creosote oil
  • 5 UU + 1 lava = 31 lava
  • 1 UU + 1 crushed ice = 2 crushed ice
  • 1 UU + 1 IC2 coolant = 3 IC2 coolant

In all cases, the energy cost for each step of Refinery operation will be UUAmount * baseConversionCost, which we'll default to 5 MJ, resulting in 15 MJ for UU -> oil, 25 MJ for UU -> fuel, 5 MJ for UU -> crushed ice.

Detailed rationale follows:


  • 1 bucket of oil = 60,000 MJ
  • 1 bucket of fuel = 600,000 MJ
  • Cost to convert 1 oil to 1 fuel = 12,000 MJ (12 MJ * 1,000 ticks)

The first two lines would suggest a ratio of 10/1 between oil and fuel, but 1 oil turns out to be equivalent to 1 fuel minus a very small refining cost, so we will consider oil to be functionally equivalent to fuel in terms of power output. Oil is otherwise our core starting point for conversion ratios, and the previous 1:1 conversion tended to be somewhat over-powered, so we'll re-evaluate it to 3 UU = 1 oil.

Fuel and oil are not directly equivalent, however -- converting oil into fuel requires a bit of extra setup and more machines that must be kept operational. This is something we wish to encourage, and therefore we must ensure that duplicating fuel is a somewhat more lossy process than duplicating oil. The simplest way to do that is to reduce fuel duplication's effectiveness, for instance to 5 UU = 1 fuel.

This gives us two calibration ratios (ignoring refining costs): either 200,000 MJ per UUM for work-intensive processes (such as oil to fuel), or 120,000 MJ per UUM for convenient processes (such as duplicating fuel directly). These will be the ratios we want to keep when deciding on the other duplicable liquids.


According to the Forestry wiki, biofuel is 1/3rd as much energy as Buildcraft fuel, which makes this a convenience duplication and gives us a very straight-forward conversion ratio of 5 UU = 3 biofuel, matching the 5 UU = 1 fuel above.


When using a still, 10 biomass turn into 3 biofuel, whereas using a refinery 4 biomass turn into 1 biofuel. Thus, we have two possible ratios:

  • 10 biomass = 600,000 MJ, OR
  • 12 biomass = 600,000 MJ

Picking between the two is mostly arbitrary, but we may as well give the still its intended bonus, so we pick the latter. This is not a convenience duplication, therefore using our UUM-to-oil conversion as the base ratio, which gives us 3 UU = 12 biomass.

When using a refinery to process the biomass, this produces 3 biofuel (or 600,000 MJ), but if using a still, you will obtain 3.6 biofuel, or 720,000 MJ.

Apple Juice

Apple juice is a 1.5x modifier for biomass production. Biomass production only depends on the source liquid, not on the organic input or the fertilizer (though these do affect the timing), therefore it's a straight-up multiplier: 8 buckets of apple juice will make 12 buckets of biomass. Since this is our calibration number, we can say that 3 UU = 8 apple juice.

Liquid Honey

Identical to the apple juice discussion above, therefore 3 UU = 8 liquid honey.

Seed Oil

Seed oil burns in a biogas engine at 3/5ths of the efficiency of biomass. This makes a very easy conversion: 5 seed oil = 3 biomass, or 20 seed oil = 12 biomass. We've already agreed 12 biomass == 3 UU, but seed oil cannot be further processed, so we need to use the UU cost for convenience conversions. Therefore, 5 UU = 20 seed oil.

Creosote Oil

Both creosote oil and biofuel can be burned in a railcraft steam boiler, and creosote is 1/10th as good a fuel as biofuel. Like the biofuel and seed oil conversions, this is a convenience duplication (creosote cannot be further processed), which therefore gives us the very easy equivalency 5 UU = 30 creosote oil.


Lava is 20,000 MJ in a combustion engine, therefore we can directly calibrate against the fuel ratio: 30 lava = 1 fuel, therefore 5 UU = 30 lava. Again a convenience duplication, because lava also cannot be further processed.

Crushed ice

Not something with a MJ value, but extremely difficult to obtain in the first place. As such, we have plenty of leeway, and we'll pick 1 UU = 1 crushed ice, making this the third category of conversions (non-fuel conversions).

IC2 coolant

Coolant is half as effective as crushed ice, so double the conversion ratio: 1 UU = 2 IC2 coolant.


Water is exceptionally easy to make for free. Converting UU to water would be a net loss in all cases, therefore we will not have any conversion ratio for it.