How do you calculate good ramp capacity?

Multiply output per cycle by available cycles for gross capacity, then multiply by uptime and first-pass yield. With 6 chargers/cycle x 120 cycles = 720 gross, times 82% uptime and 88% yield, good capacity is about 519.55 units.

What is the production ramp gap?

It is the difference between gross capacity and good shippable output. Here gross is 720 but good capacity is only 519.55, a gap of roughly 200 units lost to downtime (129.6) and defects (70.85) during the ramp.

Why separate downtime losses from yield losses?

They have different fixes. Downtime loss (129.6 units) points to line stability, parts flow, and maintenance; defect loss (70.85 units) points to process control and operator training. Splitting them tells you where to spend ramp-improvement effort.

What is a realistic first-pass yield during a charger ramp?

Early ramps often sit in the 80-90% range before stabilizing toward 95%+ at maturity. The 88% default reflects a maturing line; a brand-new DC fast-charger build with complex power electronics may start lower.

Why is gross capacity misleading for delivery commitments?

Gross assumes perfect uptime and zero scrap, which never holds during ramp. Committing 720 units when the line will realistically yield 519.55 sets up a ~28% miss and broken customer promises.

How do I close the ramp gap fastest?

Attack the larger loss first. Here downtime (129.6 units) outweighs defects (70.85), so stabilizing uptime from 82% toward 90%+ recovers more output than an equivalent yield gain — though both compound.

EV Charging Infrastructure Manufacturing calculator

Production Ramp Gap Calculator

The production ramp gap shows the difference between an EV charger line's theoretical output and the good, shippable units it will actually deliver during ramp-up. Operations and program managers use it to set honest delivery commitments when standing up a new charger product, where early uptime and first-pass yield are well below steady-state. It deflates gross capacity by two realities of a ramp — downtime from line instability and parts disruption, and scrap and rework from immature processes. The result is a defensible good-capacity number and a clear view of where ramp output leaks away.

What this calculator does

Estimate good charger production capacity during ramp from output per cycle, available cycles, uptime, and first-pass yield.
a production manager needs to compare ramp capacity with planned charger demand
It computes good ramp capacity by taking gross capacity (output per cycle x available cycles) and multiplying by expected uptime and first-pass yield, while breaking out the units lost to downtime and to defects.

Formula used

Gross ramp capacity = chargers per ramp cycle × available ramp cycles
Good ramp capacity = gross ramp capacity × expected ramp uptime × expected ramp first-pass yield

Inputs explained

Chargers produced per ramp cycle:
Available ramp production cycles:
Expected ramp uptime:
Expected ramp first-pass yield:

How to use the result

Use it when committing ramp volumes for a new charger build, validating a production plan, or quantifying the cost of low yield and uptime during launch.
It applies single ramp-average uptime and yield figures, but both improve over a learning curve, so a flat estimate understates late-ramp output and overstates early-ramp output.

Current U.S. benchmarks

Global copper trades at $13,484 per tonne (IMF via FRED, May 2026), up 41.5% in a year, and U.S. industrial electricity averages 8.66 cents per kWh. Both feed electrified-hardware unit economics.

Common questions

How do you calculate good ramp capacity? Multiply output per cycle by available cycles for gross capacity, then multiply by uptime and first-pass yield. With 6 chargers/cycle x 120 cycles = 720 gross, times 82% uptime and 88% yield, good capacity is about 519.55 units.
What is the production ramp gap? It is the difference between gross capacity and good shippable output. Here gross is 720 but good capacity is only 519.55, a gap of roughly 200 units lost to downtime (129.6) and defects (70.85) during the ramp.
Why separate downtime losses from yield losses? They have different fixes. Downtime loss (129.6 units) points to line stability, parts flow, and maintenance; defect loss (70.85 units) points to process control and operator training. Splitting them tells you where to spend ramp-improvement effort.
What is a realistic first-pass yield during a charger ramp? Early ramps often sit in the 80-90% range before stabilizing toward 95%+ at maturity. The 88% default reflects a maturing line; a brand-new DC fast-charger build with complex power electronics may start lower.
Why is gross capacity misleading for delivery commitments? Gross assumes perfect uptime and zero scrap, which never holds during ramp. Committing 720 units when the line will realistically yield 519.55 sets up a ~28% miss and broken customer promises.

Last reviewed 2026-05-12.