Mix Ratio by Weight Calculator
Precise Industrial & DIY Mixing Tool for Resins, Paints, and Silicones
The final total amount of material you need.
Please enter a positive weight.
Grams (g)
Kilograms (kg)
Pounds (lbs)
Ounces (oz)
Select your scale's unit of measurement.
Example: For a 2:1 mix, enter 2.
Please enter a valid ratio number.
Example: For a 2:1 mix, enter 1.
Please enter a valid ratio number.
Total Validated Weight
1000 g
Formula: (Ratio A + Ratio B) = Total Parts
Part A Weight
666.67 g
Part B Weight
333.33 g
Total Parts
3
Part A
Part B
| Component | Ratio Input | Percentage | Exact Weight |
|---|
Table: Detailed breakdown of the mix ratio by weight calculator results.
What is a Mix Ratio by Weight Calculator?
A mix ratio by weight calculator is a critical tool for anyone working with two-part materials such as epoxy resins, silicone rubbers, polyurethanes, or automotive paints. Unlike mixing by volume, which can be inaccurate due to the varying densities of different liquids, mixing by weight offers the highest level of precision.
This calculator helps you determine exactly how much of Part A (usually the base or resin) and Part B (the hardener, catalyst, or activator) you need to combine to reach a specific target total weight. Whether you are a DIY enthusiast casting jewelry or an industrial professional coating a floor, using a mix ratio by weight calculator ensures proper curing and structural integrity of your final product.
Common misconceptions include assuming that 1:1 by volume is the same as 1:1 by weight. This is rarely true because hardeners often have a different density (specific gravity) than resins. Always refer to the manufacturer's datasheet (TDS) for the correct weight mixing ratio.
Mix Ratio by Weight Calculator Formula
To understand how the mix ratio by weight calculator works, we break down the math into simple steps. The core concept is establishing "Total Parts" and then dividing your desired total weight by these parts.
The Mathematical Derivation:
- Determine the sum of the ratio numbers: Total Parts = Ratio A + Ratio B
- Calculate the weight of one single "part": Weight Per Part = Total Desired Weight / Total Parts
- Calculate Part A Weight: Weight A = Weight Per Part × Ratio A
- Calculate Part B Weight: Weight B = Weight Per Part × Ratio B
| Variable | Meaning | Unit | Typical Range |
|---|---|---|---|
| Total Weight | Final amount of mixed material | g, kg, lbs | 10g to 100kg |
| Ratio A | Proportion of Base/Resin | Number | 1 to 100 |
| Ratio B | Proportion of Hardener | Number | 1 to 100 |
| Percentage | Relative share of the mix | % | 1% to 99% |
Practical Examples (Real-World Use Cases)
Example 1: Epoxy Resin Table Top
Scenario: You are pouring a river table and need exactly 3 kg of epoxy. The manufacturer specifies a mix ratio of 2:1 by weight.
- Inputs: Total Weight = 3 kg, Ratio A = 2, Ratio B = 1.
- Calculation: Total Parts = 2 + 1 = 3.
- Result: 3 kg / 3 parts = 1 kg per part.
- Output: You need 2 kg of Resin (Part A) and 1 kg of Hardener (Part B).
Example 2: Automotive Paint Mixing
Scenario: You are mixing clear coat for a car panel. You need 500 grams total. The ratio is 4:1.
- Inputs: Total Weight = 500 g, Ratio A = 4, Ratio B = 1.
- Calculation: Total Parts = 5.
- Result: 500 g / 5 = 100 g per part.
- Output: Mix 400 g of Clear Coat with 100 g of Activator. Using this mix ratio by weight calculator ensures the chemical reaction occurs perfectly, preventing the paint from remaining tacky.
How to Use This Mix Ratio by Weight Calculator
Follow these steps to ensure a perfect mix every time:
- Check Your Datasheet: Locate the "Mixing Ratio by Weight" on your product's label. It might say "100:30" or "2:1".
- Select Unit: Choose grams, kilograms, pounds, or ounces. Grams are recommended for high precision.
- Enter Total Desired Weight: Input how much final material you need to fill your mold or cover your surface.
- Enter Ratios: Input the values for Part A and Part B.
- Review Results: The calculator instantly displays the exact weight required for each component.
- Weighing: Place a cup on your scale, tare it (zero it out), and pour Part A until you reach the calculated value. Do not tare again; simply add Part B until the scale reads the Total Weight (or tare and weigh Part B separately if you prefer).
Key Factors That Affect Mix Ratio Results
Even with an accurate mix ratio by weight calculator, external factors can influence your success:
- Specific Gravity (Density): If you use a volume ratio (like a measuring cup) for a product meant to be weighed, you will fail. Resin is often heavier than hardener. Always weigh unless specified otherwise.
- Temperature: Cold materials are thicker and harder to mix. Hot materials cure faster. Ensure materials are at the recommended temperature (usually 70°F-75°F) before weighing.
- Scale Accuracy: For small batches (under 100g), a kitchen scale may not be precise enough. Use a gram scale with 0.1g or 0.01g accuracy for best results.
- Pot Life: Once mixed, the chemical clock starts. Ensure you have your molds ready before you calculate and mix, so you don't waste material.
- Scraping the Container: When transferring the mix, do not scrape the sides of the mixing cup too aggressively if you haven't mixed thoroughly. Unmixed material on the walls can cause soft spots.
- Material Waste: Always calculate about 5-10% more than you think you need to account for material that sticks to the mixing stick and cup.
Frequently Asked Questions (FAQ)
Why is mix ratio by weight different from volume?
Weight measures mass, while volume measures space occupied. Since Part A and Part B often have different densities (weights per gallon), a 1:1 volume mix might actually be a 100:83 weight mix. Always follow the specific instructions for your product.
Can I use this calculator for any 2-part system?
Yes, as long as you know the correct ratio numbers provided by the manufacturer. It works for epoxy, silicone, urethane, polyester, and paints.
What if my ratio is 100:45?
Simply enter "100" in the Ratio Part A field and "45" in the Ratio Part B field. The mix ratio by weight calculator handles complex ratios effortlessly.
Should I mix by weight or volume?
Weight is generally superior because it eliminates parallax errors in reading cups and accounts for density. Most professional industrial products mandate mixing by weight.
What happens if I get the ratio wrong?
Incorrect ratios can lead to uncured sticky surfaces, brittle parts, excessive heat generation (exotherm), or complete failure to harden.
Does the total weight include the container?
No. You must "tare" (zero out) your scale with the empty container on it before adding materials.
Can I add a thinner or pigment?
This calculator determines the base chemistry. Pigments and thinners are usually added as a percentage of the total mixed weight after the A and B calculation.
Is this calculator free to use?
Yes, this mix ratio by weight calculator is completely free for personal and commercial calculations.
Related Tools and Internal Resources
Explore more tools to assist with your projects:
- Epoxy Volume Calculator Estimate how much epoxy you need for a specific mold size.
- Resin Curing Time Guide Learn how temperature and humidity affect cure times.
- Paint Coverage Calculator Calculate square footage coverage for primers and topcoats.
- Silicone Density Chart Reference specific gravity values for common mold-making rubbers.
- Industrial Unit Converter Convert between imperial and metric units instantly.
- Chemical Safety Guide Essential PPE and safety protocols for handling resins.