# CIDR Calculator — yeezhan.com
> One-time pay-per-task emergency tool to make your file ready for submission.
> No credits, no balance. One payment unlocks one task result, valid for 24 hours.

Tool domain: https://cidr-calc.yeezhan.com
Skill definition: https://cidr-calc.yeezhan.com/skill/SKILL.md
API documentation: https://cidr-calc.yeezhan.com/api/docs

## What this tool does
Network, broadcast, mask, usable hosts and range for any IPv4 / IPv6 CIDR block.

## Typical user problems
- Firewall rules and subnet plans need network, broadcast and usable range — off-by-one mistakes on the first/last host are classic outages.

## Parameters


## Pricing
- Watermarked preview: free, no login required
- Final clean output: $0.99 one-time per task
- Require login (email/phone OTP) to complete payment
- Result available for download 24 hours after payment

## Limitations
- Max input 20 MB