August 16, 2026 Buying Guide roaster capacityroaster sizingcapacity planningroastery planningbatch size

Coffee Roaster Capacity Planning: A Practical Sizing Calculator

Capacity Planning Is Just Arithmetic — Until It Isn’t

Most roasteries size their first roaster on a feeling: “a 5 kg should be enough.” Then they hit peak season, run 10 batches a day, and the roaster becomes the bottleneck. Capacity planning replaces the feeling with numbers you can defend to a bank or a partner.

The Inputs You Actually Need

Before any calculator, pin down:

Weekly output target (kg/week) — current and 18-month forecast
Roast days per week (e.g., 3, 4, 5)
Target batches per day (2–4 is healthy; 8+ is a red flag)
Batch size options available in the model you’re considering

The Calculation

batches_per_day = weekly_output / roast_days_per_week / target_batches_per_day
required_batch_size = batches_per_day_result  (round up to a real model size)

The goal: find the smallest model whose rated batch size keeps you at 2–4 batches/day at your forecast volume.

Worked Example

Say your 18-month forecast is 120 kg/week, you roast 4 days/week, and you want max 3 batches/day:

120 / 4 / 3 = 10 kg per batch

A 12 kg roaster gives you headroom (you’d run ~2.5 batches/day at 120 kg, and has room before hitting 3–4 batches). A 5 kg roaster would force 120 / 4 / 5 = 6 batches/day — too many.

Why “Batches Per Day” Matters More Than Batch Size

A bigger batch size isn’t automatically better. Running 2–4 batches/day:

Keeps labor sane
Reduces defect exposure (one bad batch is a smaller share of output)
Leaves room for rush orders

Running 8 batches/day on a small roaster means any delay cascades, quality checks get skipped, and the operator burns out. If your math says 6+ batches/day, you don’t need a bigger roaster necessarily — you need to either roast more days or buy the next model up.

Don’t Forget the Rest of the Line

Roaster capacity is only useful if grinding and packaging keep up:

A 12 kg roaster can output far more than a hand-sealed packaging station can pack. Plan the whole line, not just the roaster. See packaging machine selection.
Your grinder must handle the same daily kg without drifting.

Sizing by Roastery Model

Model	Typical weekly output	Sensible starting batch
Independent roastery	40–200 kg	5–12 kg
Café + roastery hybrid	20–100 kg	3–8 kg
Wholesale production	500 kg+	30 kg+ (second machine, not first)
Mobile / kiosk	< 30 kg	1–3 kg