Calculator inputs
The page uses a stacked content layout, while the calculator fields switch to three columns on large screens, two on smaller screens, and one on mobile.
Example data table
| Equipment | Ratio | Gasoline | Oil | Total Mix | Use Case |
|---|---|---|---|---|---|
| Cut-off saw | 50:1 | 5.000 L | 100 mL | 5.100 L | Concrete and masonry site cutting |
| Plate compactor | 40:1 | 4.000 L | 100 mL | 4.100 L | Soil and paving prep work |
| Demolition saw | 32:1 | 3.200 L | 100 mL | 3.300 L | Older two-stroke engine setup |
| Jobsite auger | 50:1 | 2.500 L | 50 mL | 2.550 L | Hole boring and post placement |
Formula used
The calculator treats the ratio as gasoline parts divided by oil parts. That lets one ratio work for liters, gallons, milliliters, or fluid ounces when units stay consistent.
- Oil from gasoline: Oil = Gasoline ÷ (Gasoline Parts ÷ Oil Parts)
- Gasoline from oil: Gasoline = Oil × (Gasoline Parts ÷ Oil Parts)
- Total mixture: Total = Gasoline + Oil
- Oil percentage: Oil % = (Oil ÷ Total) × 100
- Allowance total: Project Total = Per Batch Total × Batch Count × (1 + Allowance %)
- Runtime: Runtime = Project Total ÷ Consumption Rate
- Fuel cost: Total Cost = Gasoline Cost + Oil Cost
How to use this calculator
- Select the ratio required by your engine manual.
- Choose metric or imperial units.
- Pick the solve mode that matches your known value.
- Enter gasoline, oil, or total mixture as needed.
- Add batch count, allowance, prices, and hourly consumption.
- Press Calculate Mix to show results above the form.
- Review the detailed table and graph for batch and project totals.
- Use CSV or PDF buttons to save the output.
Frequently asked questions
1. What does a 50:1 gas and oil ratio mean?
It means 50 equal parts gasoline are mixed with 1 equal part two-stroke oil. In metric terms, 5 liters of gasoline needs 100 milliliters of oil.
2. Should all construction machines use premix fuel?
No. Only equipment designed for gas and oil premix should use it. Many modern engines have separate lubrication systems or use straight gasoline. Always check the engine label or manual first.
3. Why is oil shown in milliliters or fluid ounces?
Oil is usually measured in smaller volumes than gasoline. Showing the small-unit value makes field mixing faster and reduces conversion mistakes when filling bottles or measuring cups.
4. What happens if I add too much oil?
Excess oil can increase smoke, carbon buildup, plug fouling, and residue. The engine may still run, but performance and cleanliness can suffer over time.
5. What happens if I add too little oil?
Too little oil reduces lubrication and may cause overheating, scoring, or early engine wear. That is why matching the manufacturer’s ratio matters on every batch.
6. Why include allowance and batch count?
Allowance covers spillage, topping off, and site uncertainty. Batch count scales the same mix across repeated fills, helping crews buy enough materials and control cost before work starts.
7. Can I use this tool for liters and gallons?
Yes. Choose metric for liters and milliliters. Choose imperial for gallons and fluid ounces. The ratio stays correct because the calculator keeps unit relationships consistent.
8. Is the runtime estimate exact?
No. Runtime is an estimate based on your entered hourly consumption. Actual fuel life changes with load, temperature, throttle habits, maintenance condition, and operator technique.