# Epicor Concurrent License Sizing Calculator > Source: https://netray.co/tools/epicor-concurrent-license-sizing-calculator > Publisher: Netray (netray.co), AI and integration engineering for ERP and manufacturing systems. > Section: Free Tools ## Short answer Estimate how many concurrent licenses cover your user base at a chosen confidence and compare cost with named users. ## Category epicor ## Erp Epicor Kinetic ## Audience - IT manager - Epicor administrator - Finance controller ## Tool **Kind:** calculator **Currency:** $ **Inputs:** #### Total users who need access **Key:** users **Type:** number **Default:** 150 **Min:** 1 **Step:** 5 **Unit:** users #### Chance a user is logged in at peak **Key:** conc_pct **Type:** slider **Default:** 35 **Min:** 5 **Max:** 100 **Step:** 1 **Unit:** % **Help:** Take from login history during your busiest hour. #### Confidence you will not hit the cap **Key:** service **Type:** select **Default:** 0.95 **Options:** ##### 90% **Value:** 0.9 ##### 95% **Value:** 0.95 ##### 99% **Value:** 0.99 ##### 99.9% **Value:** 0.999 #### Price per concurrent license **Key:** price_conc **Type:** number **Default:** 3500 **Min:** 0 **Step:** 100 **Unit:** $ per year **Help:** Enter your quoted figure. Prices vary by contract. #### Price per named user **Key:** price_named **Type:** number **Default:** 1500 **Min:** 0 **Step:** 100 **Unit:** $ per year **Help:** Enter your quoted figure. **Outputs:** #### Peak probability per user **Key:** p **Expr:** conc_pct / 100 **Format:** decimal #### Expected concurrent users **Key:** mean **Expr:** users * p **Format:** decimal #### Standard deviation **Key:** sd **Expr:** sqrt(users * p * (1 - p)) **Format:** decimal #### Concurrent licenses needed **Key:** licenses **Expr:** min(users, ceil(mean + normsinv(service) * sd)) **Format:** integer **Primary:** true **Description:** Normal approximation of the binomial, capped at total users. #### Concurrent license cost **Key:** cost_conc **Expr:** licenses * price_conc **Format:** currency #### Named license cost **Key:** cost_named **Expr:** users * price_named **Format:** currency #### Concurrent minus named **Key:** diff **Expr:** cost_conc - cost_named **Format:** currency **Primary:** true **Description:** Negative means concurrent is cheaper at these prices. **Chart:** #### Concurrent licenses needed vs total users **Type:** line **X:** users **From:** 10 **To:** 500 **Steps:** 30 **Series:** - licenses - mean **Disclaimer:** Statistical planning aid, not a licensing opinion. Epicor license terms, metrics and prices are set by your contract. Confirm with Epicor or your reseller. ## Content **Intro:** How many concurrent licenses do you really need? If each person is logged in a fraction of the time, the number online at once is predictable. This calculator uses a binomial model with a normal approximation to size licenses for a chosen confidence level and compares the annual cost with named users. **Sections:** #### How to use it **Body:** Enter the total number of people who need access and the chance any one of them is logged in at your busiest hour. Take that figure from login history rather than guesswork. Choose a confidence level, and enter the prices from your own quote for concurrent and named licenses. The tool returns licenses needed, the cost of each model and the difference. **Bullets:** - Include occasional users such as managers and auditors in the user count. - Use peak-hour login data, not a daily average. - Check whether your contract counts sessions, modules or device types separately. #### The model **Body:** If each of N users is online with probability p, the number online follows a binomial distribution with mean N times p and standard deviation the square root of N times p times one minus p. We approximate with a normal curve and add the z score for your confidence level times the standard deviation to the mean. The result is rounded up and capped at the total user count. #### Reading the chart **Body:** The licenses line rises more slowly than the user count because larger pools smooth out peaks, so the cushion above the mean shrinks relative to size. Small teams need proportionally more headroom. If your concurrency probability is close to 100 percent, concurrent licensing saves nothing and named users are usually simpler. #### Common mistakes **Body:** Teams use average concurrency instead of peak, forget shift overlap, month-end spikes and integration or API sessions, and ignore that people leave sessions open all day. Idle sessions inflate concurrency, so a timeout policy can reduce licenses needed. Re-run the sizing at renewal with fresh login data. **Cta:** Netray can pull login and usage data from your ERP to ground this analysis. The calculator itself needs no contact. **Faq:** #### Is the result a guarantee I will never hit the limit? **Answer:** No. It is a probability at your chosen confidence level, based on the assumptions you enter. Unusual events such as an unplanned all-hands entry day can still exceed it. #### How do I estimate peak concurrency? **Answer:** Export session or login history from your system and count simultaneous sessions in the busiest hours, then divide by total users. Use several weeks, including month-end, to avoid underestimating. #### Are API or integration sessions included? **Answer:** That depends on your license terms. Some integration access may consume licenses or need specific types. Check your agreement and add any such sessions to the user count if they apply. #### When are named users better? **Answer:** When most users are online most of the day, or when a named price is low relative to the concurrent price. The comparison output shows the break-even at your quoted prices. ## Search terms epicor concurrent user licenses, epicor license sizing, epicor named vs concurrent, epicor license cost calculator, how many epicor licenses do i need, epicor license true up, epicor user count planning --- Talk to an engineer: https://netray.co/contact?intent=erp_ai | Machine catalog: https://netray.co/agent/catalog.json