Resin Mix Ratio Calculator

Dial in your perfect pour. Calculate precise epoxy resin and hardener amounts by weight or volume—no more guessing, no more wasted material.

Mix Calculator

Why Accurate Ratios Matter

Sticky Disasters

Too little hardener leaves resin tacky forever. The chemical reaction can't complete without the correct partner molecules.

Brittle Results

Excess hardener makes cured resin brittle and prone to cracking. Precision protects your artwork's longevity.

Weight vs Volume

Resin and hardener often have different densities. A 1:1 volume ratio may not be 1:1 by weight. Always check your product data sheet.

Pro Tips for Flawless Casting

  • Use two clean cups. Mix Part A and Part B separately first, then combine in a third cup and stir slowly for 3–5 minutes.
  • Scrape sides and bottom. Unmixed resin clinging to the cup walls is the #1 cause of soft spots.
  • Measure by weight when possible. A digital scale gives more repeatable results than volume markings, especially for small batches.
  • Temperature matters. Cold resin thickens and traps bubbles. Warm your bottles in a water bath to around 25–30°C (77–86°F) before mixing.
  • Record your ratios. Keep a notebook with brand, ratio, temperature, and cure results. It becomes your personal resin playbook.

Frequently Asked Questions

Can I use this calculator for UV resin?
UV resin is typically single-part and does not require mixing. This calculator is designed for two-part epoxy and polyester systems.
What if my ratio is by weight but I want to measure by volume?
Switch the calculator to "By Weight," enter your total weight, then use the conversion row to see the approximate volume equivalent based on typical epoxy density (1.1 g/ml).
How accurate is the volume-to-weight conversion?
We use an average density of 1.1 g/ml for mixed epoxy. For critical applications, always refer to your manufacturer's technical data sheet for exact specific gravity values.
Can I scale the recipe up or down?
Absolutely. Enter any total desired amount, and the calculator will maintain the exact ratio proportionally. It works for batches from 5 ml to 50 liters.