Droplets include free outbound data transfer, starting at 1,000 GiB/month for the smallest plan. Excess data transfer is billed at $0.01/GiB. For example, the cost of 1,000 GiB of overage is $10. Inbound bandwidth to Droplets is always free.
Any data transfer sent by a Droplet using a public network interface will count against the transfer pool for that Droplet’s account. All IPv6 traffic uses the public interface. Data transfer between Droplets over the VPC network uses a private network interface.
Transfer allowance is pooled cumulatively at the account level, not individually at the Droplet level. For example, if you run two Droplets for a full month, each with 1,000 GiB/month allowance, you accrue a 2,000 GiB allowance. Let’s say you transfer 1,500 GiB of data with the first Droplet, which is over its individual limit, and 100 GiB of data with the second Droplet, you would still be under the total limit of 2000 GiB by 400 GiB and would not be charged any overage fees.
Accrued transfer does not roll over between months and cannot be transferred between accounts or teams.
We collect usage data and display projections about your transfer pool, which you can view on your account’s Billing page.
Estimates are based on the assumption that the same daily averages for both the number of active Droplets and bandwidth usage will be maintained through the end of the month. Outbound data transfer and projected transfer allowance are updated once daily.
Billing alerts are triggered on the basis of actual usage, so projections of transfer in excess of the transfer pool will not trigger a billing alert until they are applied to the invoice.
You can check the full information on the Bandwidth billing here:
Hope that this helps!