Calculators
Controlled Substance Inventory Calculator
Reconcile a controlled substance perpetual inventory: expected count from receipts and dispensing against the physical count, with variance.
- Runs in your browser
- Nothing uploaded
The tool
Enter your numbers below. Results update as you type, and nothing leaves your browser.
Everything you enter stays on your own machine. Nothing is sent to us or to anyone else, which you can confirm in your browser network tab.
What people use it for
- Shift and periodic controlled substance counts
- Audit preparation
- Diversion monitoring
- Training staff on record keeping
About this tool
What the Controlled Substance Inventory Calculator does
Pharmacies and clinics must keep accurate records of controlled substances. A perpetual inventory reconciliation starts from the last count, adds receipts, subtracts quantities dispensed, wasted or returned, and compares the expected balance with a physical count. Any variance must be investigated and reported as required.
It also works as a controlled drug inventory calculator.
Formula
- Expected = opening + received − dispensed − wasted − returned
- Variance = physical count − expected
Worked example
Using the starting values in the calculator above:
| Input | Value |
|---|---|
| Opening count | 500 units |
| Received | 1,000 |
| Dispensed or administered | 1,180 |
| Wasted (witnessed) | 6 |
| Returned or destroyed | 0 |
| Physical count | 312 |
| Variance requiring investigation | 0% |
| Result | Value |
|---|---|
| Status | Discrepancy: investigate and document |
| Variance (physical − expected) | -2.0 |
| Expected balance | 314.0 |
| Variance as share of expected | -0.64% |
How to read the result
Count at a consistent time with two people, and investigate discrepancies immediately while records are fresh.
Significant losses or thefts may need to be reported to regulators within set timeframes; follow your jurisdiction’s rules.
Related calculators
- Veterinary Fee Pricing Calculator: Set a veterinary service fee from vet and technician time, consumables, equipment use, overhead and margin.
- Veterinary Lab Markup Calculator: Calculate the client price for veterinary laboratory tests from reference or in-house cost, markup, handling fee and sample collection.
- Multi-pet Discount Calculator: Calculate a multi-pet household’s total fees with tiered discounts for additional pets, and the effect on practice revenue.
- Nurse Staffing Calculator: Calculate nurses needed per shift and full-time equivalents from patient census, hours per patient day and shift length.
Browse every calculator in Healthcare Practice Calculators, or talk to us about healthcare websites and patient acquisition.
More tools and services
- 1031 Exchange Calculator
- 401(k) Contribution Optimizer
- 529 College Savings Calculator
- A/B Test Significance Calculator
- Accessible Ramp Calculator
- Accounts Payable Aging Calculator
If you would rather someone did this properly for you, we offer Web Design Services and Website Development, SEO Services: Search Engine Optimization, AI Automation Agency.
Questions
Questions about this tool
The things clients actually want to know — costs, timelines, ownership and what happens after launch.
A running record updated with every receipt and dispense, so the expected balance is always known.
Recount, review records, investigate and document; report significant losses as required.
Registrants such as pharmacies, clinics and hospitals, under their regulator's rules.
Free strategy session
Let’s build something worth finding.
Tell us where you want the business to be in twelve months. We will come back with a costed plan, a realistic timeline, and the numbers we expect to move — no obligation, no jargon.
- 30-minute call, no pitch deck
- Fixed-price proposal in 48 hours
- You own everything we build
Talk to a developer
Not a sales team
- Response time
- Within 1 business hour
- Where we work
- UK, USA & the Gulf
- Contracts
- No lock-in, monthly rolling
- Working since
- 2023