Small Batch Mixing Calculator | Resin Part A & Part B Calculator

Small Batch Mixing Calculator

Calculate exact Part A and Part B measurements for any resin brand ratio.
Perfect for small batches, jewelry, coasters, and craft projects.
No sign-ups. Instant results.

Calculator

💡 Tip: Always use a digital scale for measuring by weight. It's more accurate than volume measurements.

Example calculation

Let's calculate measurements for a small jewelry project using ArtResin (1:1 ratio):

Parameter Value
Total resin needed 100 grams
Resin ratio 1:1 (equal parts)
Add 10% buffer Yes
Part A (Resin) 55 grams
Part B (Hardener) 55 grams
Total mixed 110 grams (with buffer)

The 10% buffer (10 grams extra) accounts for waste and ensures you don't run short mid-pour.

🛒 Essential mixing supplies: Digital ScaleMixing CupsStir SticksNitrile Gloves

Common resin brand ratios

Resin Brand Ratio (A:B) Type
ArtResin 1:1 Craft/Art
Let's Resin 1:1 Craft/Jewelry
Dr Crafty 1:1 Craft/Art
Stone Coat 1:1 Table Top
TotalBoat ThickSet 2:1 Deep Pour
Famowood Glaze Coat 1:1 Table Top

⚠️ Always check your specific product label. Ratios can vary even within the same brand's product line.

Accurate resin mixing tips

⚖️ Use a digital scale

Measure by weight, not volume. Get a scale that measures to 0.1g accuracy for small batches under 100g.

🧪 Mix thoroughly

Stir for 3-5 minutes, scraping sides and bottom. Unmixed resin will have soft spots that never cure.

🕐 Work within pot time

Most resins have 30-45 minute pot time. Mix small batches if you need more working time.

🌡️ Room temperature matters

Resin works best at 70-75°F (21-24°C). Cold resin is thick and hard to mix. Warm it in warm water first.

💡 Need supplies? Shop: Resin KitsDigital ScalesMixing Cups

Why accurate resin mixing matters

Epoxy resin works through a precise chemical reaction between Part A (resin) and Part B (hardener). Getting the ratio wrong—even by 5-10%—can result in resin that never fully cures, stays tacky, or develops soft spots. This isn't just about following instructions; it's about understanding that resin chemistry requires exact proportions to cure properly.

Professional resin crafters always measure by weight using a digital scale because volume measurements are unreliable. Air bubbles, temperature variations, and pouring inconsistencies can throw off volume measurements by 10-15%. A $15 digital scale that measures to 0.1g is the best investment you can make for consistent results.

Small batch mixing is especially critical because measurement errors are magnified at smaller volumes. If you're making jewelry or small crafts with 50-100g batches, being off by even 5g can mean a 10% ratio error. Always double-check your measurements, and consider mixing 10% extra to account for waste—you can always save excess resin in a spare mold.

Small batch mixing FAQs

What is the mixing ratio for most resin brands?

Most craft resins use a 1:1 ratio by volume or weight (equal parts A and B). However, some brands use 2:1, 3:1, or 4:1 ratios. Always check your specific resin brand's instructions. Popular brands like ArtResin use 1:1, while some deep pour resins use 2:1.

Should I measure resin by weight or volume?

Always measure by weight using a digital scale for accuracy. Volume measurements can be off by 10-15% due to air bubbles and density variations. Weight is the most reliable method and what professional resin crafters use.

How much extra resin should I mix?

Mix 10-15% more than your calculated amount. This accounts for waste in mixing cups, popping air bubbles, and resin that sticks to stirring tools. Use the buffer option in this calculator to automatically add 10% extra.

What happens if I get the ratio wrong?

Incorrect ratios result in resin that never fully cures or stays tacky forever. The chemical reaction between Part A and Part B requires precise ratios. Even being off by 5-10% can ruin your project. Always use a digital scale and follow your brand's exact ratio.

Can I mix different amounts of Part A and Part B if I run out?

No, never alter the ratio specified by your resin brand. If you run out of Part A or B, you must purchase more of that specific component. Changing the ratio will cause the resin to fail. Unopened resin components typically last 1-2 years when stored properly.

Can I mix resin in any container?

Use clean, disposable plastic or silicone mixing cups with smooth interiors. Avoid paper cups (resin can soak through), foam cups (resin melts them), or cups with ridges that make thorough mixing difficult. Graduated measuring cups help you see your amounts clearly.

How long do I need to stir resin?

Stir thoroughly for at least 3 minutes, scraping the sides and bottom of your cup. Inadequate mixing is one of the most common causes of resin failure. Set a timer—most people don't stir long enough. For larger batches (over 200g), stir for 5 minutes.