How do you calculate demand variability?

Subtract minimum demand from maximum demand, divide by average demand, and multiply by 100. With max 140, min 80, and average 100, that's (140 - 80) / 100 x 100 = 60%.

What is a good demand variability percentage?

Lower is more predictable. Under roughly 30% is stable, 30-70% is moderately variable, and above 70% is highly volatile and hard to forecast — the 60% example sits in the moderate-to-high band.

How is this different from coefficient of variation?

This uses the simple range (max minus min) over the average, while coefficient of variation uses standard deviation over the mean. Range is faster but more outlier-sensitive; CV is more statistically robust.

Why does demand variability matter for safety stock?

Safety stock scales with demand uncertainty. A SKU at 60% variability needs more buffer than one at 15% to hit the same service level, because its demand swings wider around the average.

Can variability be over 100%?

Yes — if the peak-to-trough spread exceeds the average, the percentage tops 100%. That indicates extremely lumpy demand, common for intermittent or promotional items.

What time period should I use?

Match it to your replenishment cycle — weekly demand for weekly reorders, monthly for monthly. Mixing periods distorts the range and makes the percentage meaningless.

Supply Chain & Procurement calculator

Demand Variability Calculator

Demand variability expresses the swing between your highest and lowest period demand as a percentage of the average, giving planners a quick read on how erratic a SKU behaves. Inventory and S&OP teams use it to separate steady runners from spiky, hard-to-forecast items that need more safety stock or a different replenishment policy. A low percentage means demand is stable and predictable; a high percentage flags a SKU where a single forecast miss can trigger a stockout or an overstock. It's a fast triage metric before you invest in full statistical demand analysis.

What this calculator does

Measure demand variability for Supply Chain & Procurement from the minimum, maximum, and average demand.
Use it to size safety stock and forecast risk in Supply Chain & Procurement.
It computes the peak-to-trough demand spread divided by average demand, expressed as a percentage.

Formula used

Demand variability = (maximum − minimum) demand ÷ average demand × 100

Inputs explained

Lowest period demand observed:
Highest period demand observed:
Average period demand:

How to use the result

Use it to segment SKUs by volatility, set safety-stock tiers, or flag items that need closer forecasting attention.
Range-based variability is sensitive to outliers — one abnormal peak or trough can inflate the percentage even if demand is usually stable, so pair it with a standard-deviation view for critical items.

Current U.S. benchmarks

U.S. manufacturing runs at 75.6% of capacity (Federal Reserve, May 2026). New factory orders are up 2.3% year over year (Census).
Sourcing currencies as of 2026-07-02 (Federal Reserve H.10): 6.7886 CNY and 17.4524 MXN per USD. Landed-cost comparisons move with these daily rates.
U.S. iron and steel imports ran $2.1B in May 2026 (Census International Trade). The U.S. ran a trade deficit of $0.4B in the category that month. Import volumes are the pressure gauge behind tariff and reshoring decisions.

Common questions

How do you calculate demand variability? Subtract minimum demand from maximum demand, divide by average demand, and multiply by 100. With max 140, min 80, and average 100, that's (140 - 80) / 100 x 100 = 60%.
What is a good demand variability percentage? Lower is more predictable. Under roughly 30% is stable, 30-70% is moderately variable, and above 70% is highly volatile and hard to forecast — the 60% example sits in the moderate-to-high band.
How is this different from coefficient of variation? This uses the simple range (max minus min) over the average, while coefficient of variation uses standard deviation over the mean. Range is faster but more outlier-sensitive; CV is more statistically robust.
Why does demand variability matter for safety stock? Safety stock scales with demand uncertainty. A SKU at 60% variability needs more buffer than one at 15% to hit the same service level, because its demand swings wider around the average.
Can variability be over 100%? Yes — if the peak-to-trough spread exceeds the average, the percentage tops 100%. That indicates extremely lumpy demand, common for intermittent or promotional items.

Last reviewed 2026-05-12.