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CCTV DVR Storage Calculator

Free CCTV DVR storage calculator for DVR, NVR, camera bitrate, recording hours, retention days, RAID factor, and security storage planning.

Last updated: July 27, 2026

CCTV DVR storage calculator

This CCTV DVR storage calculator estimates required hard drive capacity from camera count, bitrate, recording hours, retention days, and storage overhead. It supports both DVR and NVR planning where the security team needs a quick storage check before final VMS or recorder selection. It is useful for CCTV tender reviews, ELV room planning, hard drive schedules, and storage expansion discussions. Final storage depends on codec, resolution, frame rate, motion recording, scene complexity, retention policy, RAID type, hot spare strategy, VMS overhead, manufacturer recommendations, and client security policy. Load the sample first, then adjust bitrate, camera count, recording schedule, and retention to understand the storage driver.

Inputs

Forms are empty on load. Use sample data to preview the workflow or enter your own project values.

Learn more

Formula logic, use cases, assumptions, and limits for this tool.

How this tool helps

Use this to estimate NVR storage before selecting HDD quantities. Actual storage depends on scene complexity, compression, motion recording, codec, and camera settings.

Assumptions and limits

This tool provides a planning-level result. It does not replace detailed engineering design, approved software, manufacturer data, authority requirements, or project specifications.

Typical use cases

  • Early estimation and tender support.
  • BOQ sanity checking and technical review.
  • Site discussion before final engineering verification.
  • Comparison of alternatives using consistent assumptions.

Result interpretation

Read the recommendation, warning, and confidence sections together. A result without warnings is still not an approval; it only means the entered values did not trigger built-in planning alerts.

Quick answer for common searches

CCTV storage is mainly controlled by camera count, bitrate, recording hours, retention days, compression, RAID allowance, and spare capacity.

Useful search phrases covered by this page

  • storage calculator cctv
  • dvr calculator
  • cctv storage calculator

Next checks

Use these links to move from a single calculator result to a fuller MEP design check.

Input definitions and typical values

These notes explain what each input means and which values usually produce a more reliable planning result.

Number of cameras cameras

Project input used directly in the calculation. Use measured, scheduled, manufacturer, or authority-approved values where available.

Average bitrate per camera Mbps

Project input used directly in the calculation. Use measured, scheduled, manufacturer, or authority-approved values where available.

Retention period days

Project input used directly in the calculation. Use measured, scheduled, manufacturer, or authority-approved values where available.

Recording hours per day hours

Project input used directly in the calculation. Use measured, scheduled, manufacturer, or authority-approved values where available.

RAID / formatting allowance %

Percentage adjustment used for diversity, derating, margin, reserve, or contingency. Use project-specific assumptions where available.

Spare storage margin %

Future spare capacity. 10-25% is common in early MEP planning, depending on client growth and infrastructure constraints.

Practical verification checklist

  • Confirm the selected standard profile is suitable for the project location and authority.
  • Replace sample values with project drawings, schedules, equipment data, or measured site values.
  • Review warnings, methodology, and PDF report before using the result outside early planning.
  • Verify final decisions against official standards, manufacturer data, consultant specifications, and local approvals.

Standards references for verification

For final design checks, verify calculator assumptions against the project documents and official standards bodies such as ASHRAE, NFPA, IEC, IET BS 7671, ICC, and CIBSE.

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Calculation methodology

Storage = camera count x bitrate x recording time x retention period, adjusted for RAID/formatting and spare allowance.

Inputs are treated as planning assumptions. The calculator shows warnings when entered values fall outside practical thresholds or selected standard-profile limits.

View full methodology notes

Version history

  • v1.3.6-prelaunch: Added methodology, standard profile support, version notes, and direct PDF report download.
  • v1.3.5: Calculator page added with sample data, warnings, and print-ready report layout.

Stage 2 roadmap: optional saved projects, dashboards, and shared calculation history without forcing login for free use.

Trust and verification

Every result includes assumptions, warning logic, and a downloadable report. Final engineering decisions still need qualified review, local authority approval, manufacturer data, and project specifications.

Worked example

Use the sample data button to load a realistic scenario, then download the PDF report to review inputs, results, methodology, warnings, and disclaimers in one place.