Wright's Law says that the cost of a unit declines by a consistent percentage every time cumulative production doubles. Theodore Paul Wright formalised it in 1936 for aircraft manufacturing: each doubling of cumulative output produced a roughly 20% cost reduction. The same pattern appears across industries — semiconductors, solar panels, batteries, wind turbines — and it is a powerful tool for understanding and forecasting cost decline.
The mechanism is learning and scale: as you make more, you get better at making more. Process improvements, standardisation, and volume spread fixed costs. Wright's Law predicts that the 1000th unit is cheaper than the 500th, and the 2000th is cheaper than the 1000th. The learning rate (the percentage cost reduction per doubling) varies by industry but is often stable within an industry over long periods.
Understanding and analysing cost trajectories requires asking: what is cumulative volume, and what is the historical learning rate? Building and scaling require positioning where you can ride the curve — or where your competitor cannot yet.
Section 2
How to See It
Wright's Law reveals itself when unit cost tracks cumulative production: each doubling of cumulative output brings a predictable percentage cost drop. Look for: industries where "we've made more so we're cheaper" is the norm, and forecasts that assume cost declines tied to volume rather than time alone.
Business
You're seeing Wright's Law when a manufacturer's unit cost drops every quarter as volume ramps, and the drop is proportional to cumulative output, not just current run rate. The first 10,000 units cost X; the next 10,000 cost 0.8X. The company is moving down the experience curve.
Technology
You're seeing Wright's Law when semiconductor or solar panel costs decline predictably with cumulative gigawatts or units shipped. Forecasts that assume "cost will fall Y% per doubling of cumulative capacity" are applying Wright's Law. The same logic applies to software at scale: marginal cost falls as cumulative usage grows.
Investing
You're seeing Wright's Law when an investor models a company's path to profitability by assuming cost per unit declines with cumulative production. The thesis depends on volume driving cost down along a predictable curve. The risk is that the learning rate slows or that a competitor reaches volume first and captures the cost advantage.
Markets
You're seeing Wright's Law when an entire industry's average cost declines as global cumulative production rises — e.g. lithium-ion batteries, PV solar. Market forecasts that plug in a learning rate and cumulative capacity are using Wright's Law. The first mover to volume often has a structural cost advantage.
Section 3
How to Use It
Decision filter
"When cost matters and volume is growing, ask: what is the relationship between cumulative production and unit cost? If Wright's Law holds, model the learning rate and cumulative volume. Use it to forecast cost, to value scale, and to decide when to commit to capacity."
As a founder
If you are in a business where unit cost falls with volume, Wright's Law is your roadmap. Know your learning rate — from your own data or from the industry. Plan capacity and pricing assuming that the next doubling of cumulative output will cut cost by that percentage. The strategic move is often to get to volume faster so you ride the curve before competitors do.
As an investor
When evaluating a company in a Wright's Law industry, check whether the cost trajectory matches the learning curve. Companies that are ahead on cumulative volume should have a cost advantage; those that are behind will face margin pressure. The thesis should explicitly model cumulative production and learning rate.
As a decision-maker
Use Wright's Law to set expectations for cost decline. If the organisation assumes cost will fall with time, but the real driver is cumulative volume, you will systematically misforecast. Align incentives and capacity decisions with the volume-cost relationship.
Common misapplication: Assuming Wright's Law holds everywhere. Some products do not show a stable learning rate; some costs are dominated by raw materials or regulation, not by cumulative production. Use the model where history supports it.
Second misapplication: Confusing current volume with cumulative volume. The cost decline is a function of total units ever produced, not this quarter's output. A company that just ramped volume has less cumulative production than a long-standing incumbent and may be higher cost for a while.
Tesla's cost strategy for batteries and vehicles assumes Wright's Law: each doubling of cumulative production drives cost down. Gigafactories are built to accelerate cumulative volume so Tesla moves down the curve faster. The bet is that volume leadership today compounds into cost leadership tomorrow.
NVIDIA's GPU cost and performance improvements follow a volume-learning dynamic: more chips shipped, better processes, lower cost per unit. Huang has pushed scale and integration to ride the curve and to make it harder for others to catch up on cumulative volume.
Section 6
Visual Explanation
Wright's Law — Unit cost falls by a consistent percentage each time cumulative production doubles. Learning rate varies by industry; volume leadership compounds.
Section 7
Connected Models
Wright's Law sits with the experience curve, economies of scale, and compounding. The models below either formalise the same idea or extend it.
Reinforces
The Experience Curve
The experience curve (BCG) is the same idea: cost declines with cumulative experience, often at a consistent rate per doubling. Wright's Law is the quantitative formulation. The two are used interchangeably in strategy and forecasting.
Reinforces
Economies of Scale
Economies of scale mean unit cost falls as volume increases. Wright's Law specifies that the driver is cumulative volume and that the relationship is predictable (percentage per doubling). Scale is the mechanism; cumulative production is the measure.
Leads-to
Compounding
Cost improvement compounds: each doubling reduces cost, which can enable more volume, which leads to the next doubling. Wright's Law describes one dimension of compounding — the cost side. Volume-cost compounding can create durable advantage.
Tension
Moore's Law
Moore's Law is about performance doubling on a time schedule; Wright's Law is about cost falling with cumulative output. Both describe predictable improvement, but one is time-based and one is volume-based. In semiconductors, both apply.
Section 8
One Key Quote
"Each time the quantity of production is doubled, the amount of labor required is reduced by a constant percentage."
— Theodore Paul Wright, Factors Affecting the Cost of Airplanes (1936)
Wright stated it for labour; the same relationship holds for total unit cost in many industries. The constant percentage is the learning rate. The doubling is cumulative production. That simple rule has predicted cost decline in aircraft, chips, solar, and batteries for decades.
Section 9
Analyst's Take
Faster Than Normal — Editorial View
Wright's Law is one of the most reliable predictors of cost decline in manufacturing and technology. When you have historical data on cumulative production and unit cost, you can estimate the learning rate and project forward. That projection is often more accurate than "cost will fall because technology improves."
Volume leadership compounds. The company that reaches cumulative volume first gets to the low-cost position first. That can fund more capacity and volume, which deepens the advantage. Wright's Law explains why "first to scale" is often "first to sustainable margin" in experience-curve industries.
Use it to forecast and to value. If you are building or investing in a Wright's Law industry, model cumulative production and the learning rate. The company that is ahead on cumulative volume should have better unit economics; the one that is behind will need to catch up or accept higher cost for longer.
Do not assume it holds everywhere. The learning rate can shift when technology or process changes. Raw material costs can dominate and break the relationship. Use Wright's Law where the data supports it — and when it does, take it seriously.
Section 10
Summary
Wright's Law says unit cost declines by a consistent percentage each time cumulative production doubles. Understanding and analysing cost trajectories requires modelling the learning rate and cumulative volume. Building and scaling in experience-curve industries means positioning to ride the curve — volume leadership today compounds into cost leadership tomorrow.
The original formulation. Wright showed that labour required per unit fell by a constant percentage with each doubling of cumulative production in aircraft manufacturing.
BCG generalised the experience curve across industries. The book connects Wright's Law to strategy: gain share to gain volume, gain volume to gain cost advantage.
Energy and climate literature often use Wright's Law to forecast solar, battery, and wind cost declines. Learning rates are estimated and updated from global cumulative capacity data.
Academic treatment of learning curves and organisational learning. Wright's Law is a special case; the literature extends to teams, plants, and knowledge transfer.
Reinforces
Learning Curves
Learning curves describe how performance or cost improves with repetition. Wright's Law is a specific form: cost as a function of cumulative production with a stable percentage reduction per doubling.
Leads-to
Inflection Point
When cost crosses a threshold (e.g. grid parity for solar), demand can inflect and volume can explode — which drives more cost decline via Wright's Law. The inflection point is often where the curve meets a market trigger.
