How do you calculate planning horizon coverage?

Divide the number of future periods that carry an approved plan by the total periods in the horizon, then multiply by 100. With 8 planned periods out of 250, coverage is 3.2%.

What is a good planning horizon coverage rate?

Best practice is effectively 100% out to your planning fence — every period should carry a real plan. The example's 3.2% against a 95% target, a 91.8-point gap, means almost the entire horizon is running on defaults.

What does the coverage gap to target tell me?

It is coverage rate minus target in points. Here 3.2% minus 95% gives a 91.8-point gap, quantifying how much of the horizon still needs an approved plan before you can trust forward supply decisions.

Coverage vs attainment — what's the difference?

Coverage asks whether a plan exists for each period; attainment asks whether the plan that existed was actually met. You need coverage first — you cannot attain a plan you never made.

Why do periods end up without a plan?

Common causes are new SKUs not yet forecasted, statistical models that only run near-term, or manual planners running out of time before the fence. Full coverage requires the process to reach every period, every cycle.

How long should the planning horizon be?

Set it to at least your longest cumulative procurement lead time plus a buffer, so every supply commitment is backed by a plan. If your horizon is shorter than lead time, coverage of 100% still leaves blind spots.

S&OP, Demand Planning & Forecasting calculator

Planning Horizon Coverage Calculator

Planning Horizon Coverage measures what share of your defined planning horizon actually has an approved demand plan in place, rather than gaps or defaults. Demand planners and S&OP leads use it to confirm the rolling horizon is genuinely populated out to the fence, not just for the next few near-term periods. It matters because procurement and capacity planning rely on forward visibility; a horizon riddled with blank periods means long-lead decisions are being made on guesswork. The metric is checked at the start of each planning cycle to catch coverage gaps before they cascade into supply. It turns an abstract worry about horizon completeness into a concrete percentage.

What this calculator does

Estimate planning horizon coverage for sandop, demand planning and forecasting using production-ready inputs so teams can track KPI performance and decide whether corrective action is needed.
Use it when planning horizon coverage in s and op, demand planning and forecasting needs a clean rate and gap-to-target you can put on a tier board.
It computes the percentage of periods in the planning horizon that carry an approved plan and the gap in points to your coverage target.

Formula used

Planning horizon coverage rate = planning horizon coverage count ÷ total planning horizon coverage population × 100
Planning horizon coverage gap to target = planning horizon coverage rate - target planning horizon coverage rate

Inputs explained

Future periods with an approved demand plan:
Total periods in the planning horizon:
Target planning-horizon coverage rate:

How to use the result

Use it at the start of a planning cycle to confirm the rolling horizon is fully populated before committing supply decisions.
It measures whether a plan exists for each period, not whether that plan is accurate — full coverage with poor forecasts still fails downstream.

Current U.S. benchmarks

The producer price index for steel mill products stands at 348.53 (BLS, May 2026), up 6.7% from a year earlier. Quotes priced off last quarter's material cost miss this move.
The U.S. has 3,569 primary metal manufacturing establishments employing about 354,911 workers (Census County Business Patterns, 2023).

Common questions

How do you calculate planning horizon coverage? Divide the number of future periods that carry an approved plan by the total periods in the horizon, then multiply by 100. With 8 planned periods out of 250, coverage is 3.2%.
What is a good planning horizon coverage rate? Best practice is effectively 100% out to your planning fence — every period should carry a real plan. The example's 3.2% against a 95% target, a 91.8-point gap, means almost the entire horizon is running on defaults.
What does the coverage gap to target tell me? It is coverage rate minus target in points. Here 3.2% minus 95% gives a 91.8-point gap, quantifying how much of the horizon still needs an approved plan before you can trust forward supply decisions.
Coverage vs attainment — what's the difference? Coverage asks whether a plan exists for each period; attainment asks whether the plan that existed was actually met. You need coverage first — you cannot attain a plan you never made.
Why do periods end up without a plan? Common causes are new SKUs not yet forecasted, statistical models that only run near-term, or manual planners running out of time before the fence. Full coverage requires the process to reach every period, every cycle.

Last reviewed 2026-05-12.