What is storage capacity?
Storage capacity is the total amount of data a computer, server, or storage device can store, typically measured in bytes such as KB, MB, GB, or TB. It determines how many files, applications, databases, and system resources a device can hold efficiently.
Individuals may need limited storage for smaller file types and basic file sizes, while businesses often require higher capacity for enterprise applications, large datasets, or systems like a desktop database. Organizations managing unstructured data or metadata commonly use scalable cloud-based object storage solutions to securely store and retrieve large volumes of information.
TL;DR: Storage capacity definition explained
Storage capacity directly impacts system performance, scalability, and cost efficiency. Understanding the difference between raw, usable, and effective capacity enables smarter infrastructure decisions, and proper capacity planning helps businesses avoid slowdowns and support growing workloads across applications, databases, and cloud environments. Best practices include scalability planning, vendor evaluation, and usage controls to manage sustainable data growth.
What are storage capacity units?
Vendors measure data storage capacity in bytes, a unit of digital information. Understanding the hierarchical system of bytes helps companies select the correct amount of storage.
- A byte (B) is the building block of the hierarchy, comprising eight bits. A byte is enough to store a single letter, number, or character.
- A kilobyte (KB) is the equivalent of 1,024 bytes and represents small amounts of data. A very short, text-only email is typically around a KB of data.
- A megabyte (MB) equals 1,024 KBs or roughly one million bytes. Larger files, like images, video clips, or audio files, are often measured in MBs.
- Gigabyte (GB) is 1,024 MBs or one billion bytes, a significant amount of data. Colloquially called a “gig,” a GB is a common unit of measurement for storage devices like hard drives or memory cards. The typical computer user who stores files, images, and videos but doesn’t game might opt for 500 GB of hard disk space.
- A Terabyte (TB) consists of 1,024 GBs or one trillion bytes. While consumer hard drives are available in a one-terabyte size, this unit typically measures the storage capacity of enterprise-level storage systems or data centers.
- A petabyte (PB) is an immense amount of data, equal to 1,024 TBs or one quadrillion bytes. Rarely used for individual storage devices, petabytes depict the total storage capacity of large networks or server farms.
How to describe storage capacity
Storage capacity is described using three key measurements: raw capacity, usable capacity, and effective capacity. These terms help organizations understand how much total space a system provides versus how much data it can actually store after accounting for system requirements and data optimization.
- Raw capacity is the total storage capacity of a system or device, or the maximum amount of data that the device can hold. Raw capacity doesn’t account for disk space reserved for formatting, system overhead, or data protection mechanisms.
- Usable capacity, also referred to as net capacity, is what remains after accounting for system files and formatting requirements that take up space on the device. Usable capacity is typically lower than raw capacity, but it provides a clearer picture of the amount of data a system or device holds.
- Effective capacity is the amount of storage space available after accounting for data reduction. Since effective capacity is based on assumptions of the data’s ability to reduce or compress, it should be considered an estimate.
What are the best practices for storage capacity?
Effective storage capacity planning requires assessing current usage, forecasting future data growth, prioritizing scalability, and selecting reliable storage solutions. Following best practices ensures systems remain efficient, cost-effective, and capable of handling increasing file sizes and diverse file types.
- Conducting a needs assessment. Evaluate current storage usage, data types (structured and unstructured), access frequency, and remaining usable capacity. Factor in growth trends and future storage demands.
- Prioritizing scalability. Choose storage systems that scale vertically (upgrading existing hardware) or horizontally (adding servers or devices) to support expanding data requirements.
- Considering cloud storage. Cloud-based storage solutions provide flexible, secure, and cost-efficient options for scaling capacity and managing large datasets.
- Evaluating vendors carefully: Consider reliability, performance, security standards, customer support, and long-term cost, not just total storage capacity.
-
Setting volume quotas. Implement usage limits and alerts to prevent capacity overload and maintain optimal system performance.
What is raw vs. storage capacity?
Raw capacity and storage capacity are often used interchangeably, but they represent different measurements of available space on a device or system. Understanding the distinction helps organizations accurately assess how much usable storage they actually have after accounting for system overhead and formatting requirements.
| Raw capacity | Storage capacity |
| The total physical storage space available on a device before formatting, redundancy, or system overhead is applied. |
The actual amount of storage available for saving files and data after accounting for system files, formatting, and reserved space. |
Frequently asked questions about storage capacity
Have unanswered questions? Let’s tackle them.
Q1. How do I find my storage capacity?
You can find your storage capacity by checking your device’s system settings under storage or disk information. This section shows total capacity, used space, and available space, helping you understand how much room remains for different file types and file sizes.
Q2. What is kb, MB, GB, TB, smallest to largest?
From smallest to largest, storage units are KB (kilobyte), MB (megabyte), GB (gigabyte), and TB (terabyte). Each unit measures file size and storage capacity, with 1,024 kilobytes equaling 1 megabyte, 1,024 megabytes equaling 1 gigabyte, and 1,024 gigabytes equaling 1 terabyte. Small file types like text documents are usually measured in KB or MB, while large files such as CAD files, videos, or desktop databases are often measured in GB or TB.
Q3. How do I increase my storage capacity?
You can increase storage capacity by deleting unnecessary files, compressing large file sizes, upgrading hardware, or using cloud storage solutions. Removing unused applications, duplicate file types, or outdated data can immediately free up space. For long-term expansion, organizations that regularly perform data export may need to upgrade to a larger hard drive, SSD, external storage device, or scalable cloud storage solution.
Q4. How much GB do you need on a phone?
Most users need between 64GB and 256GB of storage on a phone, depending on usage and file size requirements. Light users who mainly store apps and photos may manage with 64GB, while users who store high-resolution videos, large file types, or work-related files may require 128GB or more. If you download large files or store complex file types like media projects or design files, higher storage capacity ensures smoother performance and fewer storage limitations.
Learn more about file sizes on G2.
Kelly Fiorini
Kelly Fiorini is a freelance writer for G2. After ten years as a teacher, Kelly now creates content for mostly B2B SaaS clients. In her free time, she’s usually reading, spilling coffee, walking her dogs, and trying to keep her plants alive. Kelly received her Bachelor of Arts in English from the University of Notre Dame and her Master of Arts in Teaching from the University of Louisville.
