Calculators for security & electrical technicians
No sign-up, no clutter. Just the numbers you need on site — NVR storage, camera bandwidth, and battery capacity.
Featured Calculators
View All CalculatorsNVR Storage Calculator
Work out exactly how many terabytes you need for any number of cameras, resolution, and retention period.
CCTV & IP CameraIP Camera Bandwidth Calculator
Calculate total network bandwidth for a camera install so your switch and NVR ports aren't overloaded.
Electrical & WiringVoltage Drop Calculator
Check delivered voltage, drop percentage, and maximum cable length for DC or AC single-phase/three-phase runs.
Electrical & WiringWire Size Calculator
Find the right copper or aluminum AWG for your load with NEC ampacity, derating and a voltage drop check.
Battery & UPSBattery Backup Calculator
Size a backup battery for alarm panels, NVRs, or PoE switches based on standby load and runtime.
Battery & UPSAmp Hour Calculator
Convert watts, amps, and runtime into the battery amp-hour capacity you actually need.
Networking & PoEPoE Budget Calculator
Check switch power headroom, port limits, and how many cameras a PoE budget can support.
Browse Calculators by Category
CCTV & IP Camera 4
Storage sizing, bandwidth planning, and field-of-view math for camera systems.
Electrical & Wiring 4
Cable, voltage-drop and box-fill calculations for camera, security and electrical installs.
Battery & UPS 3
Backup runtime and amp-hour sizing for panels, NVRs, and switches.
Networking & PoE 1
Switch power budget and port planning for PoE camera installs.
Learn & Guides
View All GuidesNVR Storage Calculation: 12 Mistakes That Leave You Short on Space
The formula is simple — 12 real-world factors are why the calculated number is often wrong.
PoE Budget Calculator: How Many Cameras Can Your Switch Run?
Port count isn't the same as power budget — the math behind cameras rebooting after dark.
Analog vs. IP CCTV in 2026: Which Should You Actually Install
A balanced breakdown of when each system makes sense — not just "newer is always better."
How to Choose the Right Battery Size for a Security Panel
Exact Ah calculation, series vs. parallel wiring, and why lithium usually wins now.
Why GaugeCalc?
GaugeCalc is a set of free calculators and guides for CCTV, PoE and electrical installers, built and maintained by Ali Zafar. The results are for planning, so check them against the manufacturer's datasheet and your local requirements.
Every tool on this site is free, requires no sign-up, and runs entirely in your browser — your project details never leave your device.