How do I calculate the batch size for each epoxy pour layer?

Divide your total project volume equally across the number of layers. Each layer gets: Total fl oz ÷ number of layers. Add your waste buffer (10%) to each batch. For example: 200 fl oz total ÷ 4 layers = 50 fl oz per layer + 10% buffer = 55 fl oz per batch.

Should each pour layer be the same thickness?

For river tables: yes, equal layers are simplest to manage. For floor coatings: a thin seal coat first (thinner than build coats) helps with adhesion on porous surfaces. For artistic layers with pigment variations: layers can vary, but each must stay within the resin's maximum safe depth.

Epoxy Pour Calculator — Plan Your Layers & Batch Sizes

Q: How long should I wait between epoxy pours?

Pour the next layer when the previous one is at a firm gel stage — solid enough to not mix but still tacky. For standard resin: 6–12 hours. For deep-pour resin: 24–48 hours. If the previous layer has fully cured (hard and glossy), lightly sand it before pouring the next layer to ensure adhesion.

Q: Can I pour all layers in one day?

Possibly, depending on your resin's gel time. Pour the next layer when the previous one is at a firm gel — this bonds the layers chemically rather than mechanically. Check your product's recoat window. For standard resins, a 2-layer table can often be completed in 12–24 hours.

Multi-layer epoxy projects need a plan before the first pour. Without one, you risk running out mid-project, pouring too thick and cracking your work, or having layers that don't bond properly. This guide walks through calculating per-layer batch sizes, timing between pours, and total project volume. Use the free epoxy calculator and set your number of pours to get a per-layer breakdown automatically.

Set the number of pour layers in the calculator — get per-layer volume and total batch sizes instantly.

🌊 Plan Your Pour Schedule ⟶

🔢 Per-Layer Batch Formula

Calculating Batch Size for Each Layer

The total epoxy volume doesn't change with more layers — you're distributing the same amount across multiple pours. Calculate the per-layer batch size:

Per-layer net volume = Total net volume ÷ Number of layers
Per-layer batch (with buffer) = Per-layer net × (1 + waste buffer %)

Example: River table with 300 fl oz total at 3 pours, 10% buffer:
Per-layer net = 300 ÷ 3 = 100 fl oz. Per-layer batch = 100 × 1.10 = 110 fl oz per pour.
For 2:1 mix ratio: Part A = 73.3 fl oz, Part B = 36.7 fl oz per batch.

⏱️ Pour Timing Guide

When to Pour Each Layer

Timing between layers is critical. Pour too soon and you disrupt the curing layer; wait too long and layers won't bond without sanding.

Resin Type	Recoat Window	Surface State	If Window Missed
Standard coating resin	6–12 hours	Firm gel, still tacky	Sand lightly before next pour
Tabletop / bar top resin	8–16 hours	Firm, slightly tacky	Sand with 120-grit, clean dust
Deep-pour casting resin	24–48 hours	Firm gel, may not be tacky	Sand with 80-grit for adhesion
UV resin	Immediately after lamp cure	Hard but not polished	Sand or re-prime surface

The ideal window is when the previous layer is at a firm gel stage — it holds your fingerprint without deforming, but still has a slight tack. This creates a chemical bond between layers, not just a mechanical one.

📋 Pour Schedule Examples

Sample Pour Plans by Project

Project	Total Depth	Resin Type	Layers	Schedule
Shallow river table	¾″	Standard	3	Pour 1 → 8h → Pour 2 → 8h → Pour 3
Deep river table	2″	Deep-pour	1	Single pour; 48h cure
Deep river table	3″	Deep-pour	2	Pour 1.5″ → 36h → Pour 1.5″
Garage floor	1/8″ × 2 coats	Floor epoxy	2	Seal coat → 12h → Build coat → 24h
Bar top	¼″ × 2 coats	Tabletop	2	Seal → 8h → Flood coat → 24h cure

Frequently Asked Questions

How do I calculate batch size for each pour layer?

Divide total project volume by number of layers for the per-layer net volume. Add your waste buffer (10%) to get the per-layer batch size. The calculator does this automatically when you set the number of pours — it shows both total and per-layer volume.

How long should I wait between epoxy pours?

Pour when the previous layer reaches a firm gel stage: solid enough to hold a fingerprint without deforming, but still slightly tacky. For standard resin: 6–12 hours. For deep-pour: 24–48 hours. Always check your specific product's recoat window — exceeding it requires sanding for adhesion.

Can I pour all layers in one day?

Possibly with fast-cure standard resins. If gel time is 4–6 hours, two layers can be done in a day. However, deep-pour resins need 24–48 hours between layers and cannot be rushed. Check your product's gel time and plan your schedule accordingly.

Do I need equal thickness in each layer?

For structural pours (river tables, casting): equal layers are simplest. For floor coatings: a thinner seal coat first, then thicker build coats. For artistic effects with color variation: layers can vary in thickness, provided each stays within the resin's maximum safe depth.

Epoxy Pour Calculator — Plan Your Layers & Batch Sizes

Calculating Batch Size for Each Layer

When to Pour Each Layer

Sample Pour Plans by Project

Frequently Asked Questions

Related Guides & Calculators