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Restaurant Inventory Days Calculator

Estimate how many days restaurant inventory will last from current stock and daily usage, or from beginning/ending inventory and COGS — with optional safety buffer and waste %.

Inventory days

Formula
Mode 1: Inventory Days = Current Inventory ÷ Average Daily Usage
Mode 2: Average Inventory = (Beginning + Ending) ÷ 2
Daily Usage = COGS ÷ Period Days
Inventory Days = Average Inventory ÷ Daily Usage
Usable Inventory Days = Inventory Days − Safety Buffer Days

What it means

Divide stock by how much you use per day. In COGS mode, daily usage is period COGS divided by period days. Optional waste % reduces effective stock; a safety buffer subtracts reserved days from usable coverage.

Good to know

  • Daily usage is steady across the coverage window.
  • COGS mode period lengths: weekly 7, monthly 30, quarterly 90, yearly 365.
  • Waste % and safety buffer default to zero when blank.

Ideal range

  • Does not model delivery lead times or reorder points.
  • Category mix (produce vs dry goods) can hide risk inside an overall average.

Variables

Inventory DaysDays on hand
How long stock lasts at the current daily usage rate.
Usable Inventory DaysCoverage after buffer
Inventory days minus safety buffer — the days you can plan without dipping into cushion.
Expected Waste %Spoilage adjustment
Optional reduction of effective inventory before dividing by daily usage.

Worked examples

Real numbers through the same formula this tool uses.

  1. 1
    Restaurant scenarioExample 1

    Direct days on hand

    $7,000 inventory ÷ $1,000 daily usage = 7.0 days remaining (excellent).

  2. 2
    Restaurant scenarioExample 2

    From monthly COGS

    Flat $7,000 average stock and $30,000 monthly COGS → $1,000/day → 7.0 days.

  3. 3
    Restaurant scenarioExample 3

    Waste and safety buffer

    $10,000 stock, $1,000/day, 10% waste → 9.0 days; minus 2-day buffer → 7.0 usable days.

How to use this calculator

Turn stock dollars into days of coverage — directly or from a COGS period.

  1. Choose direct usage or COGS mode

    Use direct when you know daily usage. Use COGS when you have period counts and COGS.

  2. Enter inventory and usage (or COGS)

    Match currency and period. In COGS mode, select weekly, monthly, quarterly, or yearly.

  3. Optionally add waste % and a safety buffer

    Waste shrinks effective stock; buffer reserves days you do not want to spend.

  4. Read days remaining, usable days, and health

    Compare to restaurant bands, then refine with Inventory Turnover.

What are inventory days?

Inventory days estimate how long current or average stock will last at today’s usage rate — complementary to inventory turnover.

  • Days on hand

    Divide inventory by average daily usage. The result is how many days of stock you effectively hold.

  • Inventory days vs inventory turnover

    Turnover counts cycles in a period. Days ask how long stock lasts. Roughly: days ≈ period days ÷ turnover.

  • Restaurant benchmarks

    Many kitchens aim for about 7–14 days of overall food inventory. Produce is often leaner; dry goods slower.

  • How to reduce excess inventory

    Tighten order guides, feature slow movers, improve forecasts, and count perishable categories more often.

Best practices

Habits that keep days-on-hand numbers actionable.

  • Keep currency and period aligned

    Inventory and usage must share the same unit. In COGS mode, match period length to the COGS window.

  • Set a realistic safety buffer

    Reserve a few days for late deliveries — then manage to usable days, not raw days.

  • Include expected waste when it matters

    High-spoilage concepts should apply a waste % so coverage is not overstated.

  • Pair with Inventory Turnover

    Days show coverage; turnover shows velocity. Use both after each count.

Common mistakes

Errors that inflate days on hand.

  • Using purchases as daily usage

    Purchases ignore stock still on the shelf. Prefer true usage or COGS-derived daily usage.

  • Wrong COGS period length

    Selecting yearly while entering monthly COGS understates daily usage and overstates days.

  • Planning to zero days

    Running without a buffer turns every late truck into a stockout.

  • One overall number for every category

    Overall days can look fine while produce ages. Review high-spoilage groups separately.

Related tools and guides

Connect days on hand to turnover, food cost, and plate cost. Future inventory tools will deepen this cluster.

  • Restaurant Inventory Turnover Calculator

    Measure turns and days of inventory from period usage.

  • Food Cost Percentage Calculator

    Measure food cost ÷ food sales for the period.

  • Recipe Cost Calculator

    Build recipe cost from ingredients and yield.

  • Plate Cost Calculator

    Roll portion and accompaniments into plate cost.

  • Prime Cost Calculator

    Combine food and labor into one controllable-cost view.

  • Restaurant Food Waste Calculator

    Estimate waste %, period cost, and annual losses from purchases or inventory loss.

  • Restaurant Reorder Point Calculator

    Calculate when to reorder from daily usage, lead time, and safety stock.

  • Restaurant Safety Stock Calculator

    Size buffers from max-min demand or demand variability and service level.

  • Coming in this cluster

    EOQ, Inventory Valuation, Stock Usage, and Purchase Order calculators are planned next.

Frequently asked questions

You may also need

Complementary calculators that often pair with this workflow.

Inventorybeginner3 min

Restaurant Food Waste Calculator

Estimate restaurant food waste cost, waste percentage, annual losses, and potential savings from purchases or inventory loss — with recovery value and reduction goals.

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Restaurant Reorder Point Calculator

Calculate when to reorder restaurant inventory from average daily usage and lead time — with optional safety stock, current levels, and suggested order quantity.

Inventoryintermediate4 min

Restaurant Safety Stock Calculator

Calculate restaurant safety stock from max-versus-average demand and lead time, or from demand variability and service level — then see protection days and a recommended reorder level.

Continue exploring

More tools to browse after you finish this calculation.

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Calculate restaurant labor cost percentage from total labor and sales. Optionally include payroll taxes and benefits for a loaded labor figure.

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Restaurant Sales Mix Calculator

Calculate restaurant sales mix from units sold and selling price per item or category. See mix %, revenue share, contribution and profit rankings, top and lowest performers, and a concentration benchmark.