# How instance traffic is counted

> How an instance's monthly traffic allowance is measured, where you see it, and what happens when you go over it.

Source: https://docs.coritan.com/cloud-compute/traffic/

Each Cloud Compute plan includes a monthly *traffic allowance*: the amount of data an instance can transfer in a calendar month. The order page shows the allowance with each plan, in terabytes. The dashboard shows how much of it each instance has used.

## What counts

- Both directions count: everything the instance receives and everything it sends.
- Traffic on every network card of the instance counts, including the cards for extra [floating IPs](/floating-ips/).
- A terabyte here is 1024⁴ bytes.

We read the instance's traffic counters every few minutes while it runs, so the figures trail the real traffic by a few minutes. A stopped instance transfers nothing, and its figures stay where they were.

> [!NOTE]
> The counters start again from zero each time the instance is stopped and started, including a restart from the dashboard. After that, the month's figure stays at its earlier value until the new count passes it, and the traffic from before the restart is not added to it. A run that began last month also brings the traffic from before the 1st into the new month.

## The monthly period

The allowance runs by calendar month, from the 1st of one month to the 1st of the next, whatever the service's billing date. Each month starts again from zero, and unused traffic does not carry over.

## Where you see it

On the instance's **Network** tab, the **Traffic** card shows the month's dates and:

**Transferred**
: A meter of the month's traffic against the allowance, with how many terabytes are left. A plan with no allowance shows `Unmetered on this plan`.

**Inbound** and **Outbound**
: The traffic received and sent this month.

**Port speed**
: The network speed of the plan.

**Metered**
: When we last read the counters.

On the **Console** tab, the **Bandwidth** card shows the traffic used against the allowance, and the date it resets.

## When an instance goes over

Going over the allowance does not stop the instance's traffic. The **Traffic** card shows `Over the plan allowance`, and we make no [backups](/cloud-compute/backups/) of the instance until the next month starts. The backups you already have stay, and you can still restore and delete them.

An instance keeps the allowance of the size you ordered. For a larger allowance, move to a new instance of a larger size, as [Get a different size](/cloud-compute/billing/#get-a-different-size) describes.

## Related

- [Manage an instance's addresses and names](/cloud-compute/networking/) describes the rest of the **Network** tab.
- [Back up and restore an instance](/cloud-compute/backups/) explains the backups that pause over the allowance.
- [Cloud Compute limits](/cloud-compute/limits/) lists the other limits of an instance.

## With the API

`GET /api/v1/client/vps/{uuid}/bandwidth` returns the instance's traffic for the month.

```bash
curl https://api.coritan.com/api/v1/client/vps/$INSTANCE_UUID/bandwidth \
  -H "Authorization: Bearer $CORITAN_TOKEN"
```

```json
{
  "period_start": "2026-09-01",
  "period_end": "2026-10-01",
  "bytes_in": 412316860416,
  "bytes_out": 137438953472,
  "bytes_used": 549755813888,
  "updated_at": "2026-09-25T10:05:00",
  "limit_tb": 2.0,
  "used_tb": 0.5,
  "remaining_tb": 1.5,
  "percent_used": 25.0,
  "over_quota": false,
  "bytes_limit": 2199023255552,
  "used": 0.5,
  "limit": 2.0
}
```

`period_end` is the first day of the next period. `limit_tb`, `remaining_tb`, `percent_used` and `bytes_limit` are `null` when the plan has no allowance, and `over_quota` is then always `false`. `used` and `limit` repeat `used_tb` and `limit_tb`.

## API

- `GET /api/v1/client/vps/{uuid}/bandwidth`: Get current billing period bandwidth usage vs plan traffic allotment (TB) (https://docs.coritan.com/api/reference/client/cloud-compute/#op-get-api-v1-client-vps-uuid-bandwidth)