How do you calculate roast curve capacity?

Multiply roasted output per batch by planned batches for gross capacity, then multiply by uptime and first-pass yield for usable capacity. With 84 lb over 22 batches at 86% uptime and 98% yield, gross is 1,848 lb and usable is about 1,557 lb.

What is the difference between gross and usable roast capacity?

Gross capacity assumes every planned batch runs at full release. Usable capacity discounts for the time the roaster is down between batches and the pounds lost to shrink and rejects, giving the poundage you can actually ship.

What roaster uptime should I assume?

During active profile runs, 80-90% is realistic once you account for cooling, charging, and minor stoppages. The 86% here means roughly one batch-equivalent in seven is lost to downtime across the planning window.

How much capacity am I losing to downtime and rejects?

In this example, downtime costs about 259 lb and shrink or rejects cost about 32 lb, so the 1,848 lb gross falls to roughly 1,557 lb usable. Downtime is the far larger lever here, worth attacking first.

When should I add a second roaster?

When usable capacity, not gross, consistently falls short of committed volume. If you are promising 1,800 lb but usable capacity is 1,557 lb, you are short and either adding a shift or a machine becomes the question.

How do I increase usable roast capacity without a new machine?

Lift uptime by sequencing similar profiles to cut cool-down and changeover, batch larger where the profile allows, and reduce rejects through tighter green QC and roast logging.

Coffee, Tea, Roasting & Dry Goods Processing calculator

Roast Curve Capacity Calculator

Roast curve capacity is the realistic finished poundage a roaster can deliver over a planning window once you account for uptime and first-pass yield, not just the nameplate batch size times the clock. Production planners and roastery owners use it to commit to wholesale volumes, schedule shifts, and decide when a second roaster or a larger machine is justified. Gross capacity assumes every batch runs back-to-back at full release, but real curves lose time to cooling, profile changes, and downtime, and lose pounds to shrink and rejects. This calculator separates the theoretical ceiling from the poundage you can actually promise.

What this calculator does

Estimate usable roasted output from roast batch size, batches per shift, roaster uptime, and roast-yield factor.
planning roasted coffee output by profile, roaster, or shift
It computes gross capacity as batch output times planned batches, then usable capacity by applying roaster uptime and first-pass release yield, and quantifies pounds lost to downtime and to shrink or rejects.

Formula used

Gross roast curve capacity = roasted output per batch × planned roast batches
Usable roast curve capacity = gross output × roaster uptime during profile run × first-pass roasted coffee release yield

Inputs explained

Roasted output per batch:
Planned roast batches:
Roaster uptime during profile runs:
First-pass roasted release yield:

How to use the result

Use it when planning weekly production, accepting a large wholesale commitment, or evaluating whether to add a shift or a second roaster.
It uses single uptime and yield figures for the window; if your machine bogs down on dark profiles or yield varies sharply by origin, blend a weighted average or model profiles separately.

Common questions

How do you calculate roast curve capacity? Multiply roasted output per batch by planned batches for gross capacity, then multiply by uptime and first-pass yield for usable capacity. With 84 lb over 22 batches at 86% uptime and 98% yield, gross is 1,848 lb and usable is about 1,557 lb.
What is the difference between gross and usable roast capacity? Gross capacity assumes every planned batch runs at full release. Usable capacity discounts for the time the roaster is down between batches and the pounds lost to shrink and rejects, giving the poundage you can actually ship.
What roaster uptime should I assume? During active profile runs, 80-90% is realistic once you account for cooling, charging, and minor stoppages. The 86% here means roughly one batch-equivalent in seven is lost to downtime across the planning window.
How much capacity am I losing to downtime and rejects? In this example, downtime costs about 259 lb and shrink or rejects cost about 32 lb, so the 1,848 lb gross falls to roughly 1,557 lb usable. Downtime is the far larger lever here, worth attacking first.
When should I add a second roaster? When usable capacity, not gross, consistently falls short of committed volume. If you are promising 1,800 lb but usable capacity is 1,557 lb, you are short and either adding a shift or a machine becomes the question.

Last reviewed 2026-05-12.