Free Tools
Planning calculators that show the math
Run the same formulas Demand OS automates at scale — forecast accuracy, safety stock, EOQ, and inventory turnover. Free, instant, with every formula explained.
Book a DemoWhat planning calculators does Demand OS offer?
Perimattic Demand OS provides four free calculators for supply chain planners: a Demand Forecast Accuracy calculator that computes MAPE and bias, a Safety Stock calculator using demand and lead time variance, an Economic Order Quantity (EOQ) calculator that balances ordering and holding costs, and an Inventory Turnover calculator that converts COGS and average inventory into turnover ratio and days of supply. Each calculator shows the formula, explains the result, and links to how Demand OS automates the same calculation at scale.
Demand Forecast Accuracy
Compute MAPE, bias, and weighted MAPE from your forecast vs actuals. See where your forecast breaks and what accuracy level Demand OS targets.
Use CalculatorSafety Stock Calculator
Calculate safety stock using demand variability, lead time variability, and your target service level. See the Z-score formula and working capital impact.
Use CalculatorEOQ Calculator
Find the economic order quantity that minimizes total ordering + holding cost. See annual cost breakdown and how Demand OS optimizes order sizing dynamically.
Use CalculatorInventory Turnover Calculator
Convert COGS and average inventory into turnover ratio and days of supply. Benchmark against industry averages and see where inventory is stuck.
Use CalculatorGet Started
Ready to automate these calculations?
Demand OS runs forecast accuracy, safety stock, EOQ, and inventory turnover at the SKU level across your entire catalogue — continuously, not once a quarter.