Factorio Oil Calculator Guide: Advanced Oil, Cracking & Petroleum Gas
A Factorio oil calculator helps you avoid the classic fluid problem: one oil product backs up, the whole refinery stops, and plastic or sulfur production starves even though crude oil is available.
Last updated: May 7, 2026. Written for Factorio 2.0 and Space Age-era oil planning.
Quick Answer: How Should You Calculate Oil in Factorio?
Oil should be calculated by desired output, not by a single universal ratio. A petroleum-focused plastic build is different from a rocket fuel build that preserves light oil or a lubricant build that preserves heavy oil.
- Decide the main output first: petroleum gas, light oil, heavy oil, lubricant or rocket fuel.
- Use cracking to convert surplus heavy oil and light oil when petroleum gas is the main target.
- Prevent fluid backup with cracking priorities, pumps, circuit control or correctly sized consumption.
- Recalculate if coal liquefaction, modules, beacons or Space Age production changes the chain.
Oil Planning Is About Byproducts
Oil processing is harder than many solid-item recipes because refineries produce multiple outputs. A calculator helps because the best setup depends on what you want to keep and what you want to crack.
Start With the Desired Oil Product
There is no one best oil ratio for every factory. The correct answer depends on whether the next bottleneck is plastic, sulfur, lubricant, rocket fuel or another oil product.
| Goal | Primary Fluid | Planning Note |
|---|---|---|
| Plastic and sulfur | Petroleum gas | Crack surplus heavy and light oil toward petroleum. |
| Rocket fuel | Light oil | Do not crack all light oil if rocket fuel is the priority. |
| Lubricant | Heavy oil | Reserve heavy oil before cracking the rest. |
| Flamethrower fuel | Light or heavy oil | Consumption is usually intermittent, so storage and priority matter. |
| Coal liquefaction backup | Mixed outputs | Useful when coal is abundant or crude oil is constrained. |
Common Oil Cracking Ratios
These ratios are useful starting points, but the best build still depends on the desired output. Treat them as planning references, not universal rules.
| Setup | Ratio | Best For | Important Note |
|---|---|---|---|
| Advanced oil to petroleum | 20 refineries : 5 heavy cracking : 17 light cracking | Petroleum gas, plastic and sulfur | A close simplified ratio is 8 : 2 : 7. |
| Coal liquefaction to petroleum | 60 liquefaction : 39 heavy cracking : 55 light cracking | Coal-rich maps and late-game backup | A close simplified ratio is 12 : 8 : 11. |
| Lubricant priority | Reserve heavy oil before cracking | Blue belts, electric engines and late-game items | Use pumps or circuits so lubricant has priority. |
| Rocket fuel priority | Reserve light oil before cracking | Rocket fuel and late-game logistics | Only crack excess light oil after rocket fuel demand is met. |
Recommended Oil Calculator Workflow
Choose the oil product bottleneck
Decide whether the factory needs more petroleum gas, light oil, heavy oil, lubricant or rocket fuel.
Calculate refinery output
Use the correct oil processing recipe and count the outputs separately instead of treating oil like one item.
Add cracking priorities
Crack surplus heavy oil to light oil and surplus light oil to petroleum only after reserved uses are satisfied.
Size chemical plants
Plastic, sulfur, lubricant and rocket fuel plants determine how much each fluid is actually consumed.
Prevent backup
Use tanks, pumps or circuits to stop one full fluid from stalling the whole oil system.
Common Oil Calculation Mistakes
| Mistake | What Happens | Fix |
|---|---|---|
| Cracking all heavy oil | Lubricant production starves later. | Reserve heavy oil for lubricant first. |
| Cracking all light oil | Rocket fuel production becomes short. | Reserve light oil before petroleum cracking. |
| No cracking control | One fluid fills and refineries stop. | Use circuit-controlled pumps or priority layouts. |
| Ignoring petroleum demand | Plastic or sulfur becomes the real bottleneck. | Calculate downstream chemical plant consumption. |
| Copying a ratio without goal context | The oil block solves the wrong problem. | Pick the desired output before choosing the ratio. |
Need a full oil production chain?
Use the live calculator for refinery counts, chemical plants, modules and downstream products, then use this guide to choose cracking priorities.
Factorio Oil Calculator FAQ
What is the best oil ratio in Factorio?
There is no single best ratio for every case. For petroleum-focused advanced oil, 20 refineries : 5 heavy cracking : 17 light cracking is a useful reference, with 8 : 2 : 7 as a close simplified version.
Why does my oil processing stop?
Usually one fluid output is full. Refineries stop when they cannot output all products, so use cracking, storage, pumps or circuits to prevent backup.
Should I crack all heavy oil?
No. Reserve heavy oil for lubricant first if your factory needs it, then crack excess heavy oil into light oil.
Should I crack all light oil into petroleum?
Only if petroleum gas is the priority. If you need rocket fuel, reserve light oil before cracking the surplus.
Is coal liquefaction worth calculating?
Yes, especially on coal-rich maps or when crude oil is constrained. It has different ratios and should be planned separately from advanced oil.
Sources and Further Reading
These references help verify current oil and cracking behavior.