# Credit cost & pricing

## How does it work?

**coherence**'s pricing is designed to be accessible for all developers, ranging from indie developers to AAA game studios.

Our platform helps you utilize compute resources efficiently in order to minimize wasteful spend. We know that forecasting cloud costs can be daunting, so **coherence** provides different **subscription plans** for different requirements, and the flexibility to change plans at any time, or purchase additional credits to deal with short term bursts or spikes in user numbers.

**coherence** uses our own **in-house virtual credit system** to convert and keep track of costs.

## Why Credits?

Since no two games are identical in their use of cloud resources, credits give you the **flexibility** you need for your Unity multiplayer game. Whether you’re building a platformer, a virtual DJ venue, a racing sim game or the next big MMO, our credit system makes sure your project gets maximum value and usage out of your chosen tier!

## Credits explained

Credits are **coherence**’s virtual unit of cost that can be converted into:

* Concurrent user hours (CCU hours)
* Simulator hours
* Bandwidth
* Game service usage
* ...and more

Detailed explanations of these terms are available in our [Glossary](https://docs.coherence.io/1.2/additional-resources/glossary).

## Calculating credit costs

{% hint style="info" %}
At Free tier, you get 30 000 credits every month, **free of charge**.

For Paid tiers (Bronze to Platinum) the cost is **1000 credits for $0.83**.

For Extra credits that are applied when you use more than your plan provides, the cost is higher at **100 credits for $0.20**.
{% endhint %}

### Rooms

The cost for a game session in a room based game is calculated easily as follows:

```
sessionCreditCost = sessionLength * maxPlayers / 60 + sessionBandwidthGB * 200
```

Where:

* **sessionLength** = the maximum duration of a game session in minutes
* **maxPlayers** = the maximum number of players that can join a game session
* **sessionBandwidthGB** = total outbound bandwidth in GB

{% hint style="warning" %}
For the purposes of our bandwidth/storage calculations, **1 GB equals 1000MB**, not 1024MB.
{% endhint %}

**Example**

Sessions per month = 150,000

Max players per session = 12

Max length of a session = 2 minutes

Outbound bandwidth per session = 2.5 MB

```
sessionCreditCost = (12 * 10 / 60 + 2.5 / 1024 * 200) * 150000 = 88,828 Credits
```

**150K sessions would cost approximately 89K credits.**

### Worlds

It's equally simple to calculate the cost for a persistent world that is online 24/7:

```
worldCreditCost = (worldSize * 24 * 30) + (averageHourlyTrafficGB * 24 * 30) * 200
```

Where:

* **worldSize** = the maximum number of players that the world can host
* **averageHourlyTrafficGB** = the average outbound bandwidth consumed hourly by the world

**Example**

Number of worlds online = 3 (24/7, eg. NA, EU, Asia)

Max players per the world = 250

Average outbound bandwidth per hour = 95 MB

```
worldCreditCost = ((250 * 24 * 30) + ((95 / 1024) * 24 * 30) * 200) * 3 = 580,078 Credits
```

**Hosting three worlds for up to 250 players would cost approximately 580K Credits.**

### Simulators

{% hint style="warning" %}
Simulators generate credit cost whenever they are online.
{% endhint %}

To calculate those costs you need to understand how many Simulator instances you require and when and for how long they will be online. For Room-based games, credit costs can be calculated with the following formula:

```
totalSimCost = (timeOnlinePerInstance / 60) * (simInstanceCost * simUtilisationPerSession)
```

**Example**

simUtilisationPerSession = 0.5 (one instance for 2 concurrent sessions)

timeOnlinePerInstance = 2 (sessionLength of room example above)

simInstanceCost = 40 (medium sim)

```
totalSimCost (per session) = (2 / 60) * (40 * 0.5) =  0.7 Credits
```

**Simulator support for 50K sessions would cost approximately 35K Credits.**

## Billing

Every month we calculate your credit cost based on the total consumption of CCU hours and bandwidth. Before we calculate the total credit cost based on the aforementioned formulas, we **deduct the included CCU hours and bandwidth** in your plan.

The base subscription fee will be invoiced at the **beginning of the month**. If you exceed your limits and require additional credits, these will be invoiced with a separate invoice at the end of the month.

## Subscription plans

Don't forget to also take a look at our [Pricing page](https://coherence.io/pricing) to:

* See the available **features** and **benefits** of various **subscription tiers**
* Understand what **Credits** are and see how many you get per tier
* See **example game costs**

## Limits and caveats

* Rooms are limited to **100 CCU**s. The total number of Rooms is unlimited provided the credit usage stays within plan limits.
* Worlds are limited to **1000 CCU**s. The total number of Worlds is unlimited provided that the credit usage is within plan limits.
* Enterprise customers can negotiate **custom sizes** for both Rooms and Worlds.
* Costs per session or World will increase if additional features such as Simulators or KV-Store are utilized.
* Each plan comes with a maximum amount of purchasable extra credits. Exceeding that limit will result in throttling CCUs and an extra charge at the end of the billing cycle for features that can't be throttled like storage.