Input Configuration
Conversion Results
Enter a value to see conversions
All supported units will be calculated automatically
About This Tool
As a developer, I constantly need unit conversions that generic converters don't handle well: converting Mbps to MB/s when setting download speed limits, calculating actual file sizes after Base64 encoding for API payloads, converting milliseconds to human-readable durations for logging, or translating px to rem for responsive CSS. This tool covers the conversions developers actually need daily. I built it with both SI (1000-based) and IEC (1024-based) modes because that MB vs MiB distinction matters when calculating disk space or network throughput. The data rate converter handles the tricky Mbps (megabits per second) to MB/s (megabytes per second) conversion that confuses even experienced engineers. All calculations happen instantly as you type, with results shown in multiple relevant units simultaneously.
How to Use
Select a conversion category (Data Size, Data Rate, Time Duration, CSS Units, etc.) from the dropdown. Enter your value in any unit field—the tool instantly converts to all other units in that category. For Data Size: toggle between SI mode (1 KB = 1000 bytes, used by storage manufacturers) and IEC mode (1 KiB = 1024 bytes, used by operating systems). For Data Rate: convert between Mbps (network speeds advertised by ISPs), MB/s (download speeds shown in browsers), and other units—remember 1 MB/s = 8 Mbps. Time Duration converts milliseconds/seconds/minutes/hours/days—useful when working with setTimeout, API timeouts, or log timestamps. CSS Units help convert px to rem/em based on root font size. The Base64 calculator shows size increase (33% overhead) when encoding files.
Common Use Cases
Network Speed Planning
ISP offers 100 Mbps; convert to 12.5 MB/s to know actual file download speed. Calculate how long a 500 MB file takes at that speed.
Storage Calculations
Database field stores file sizes in bytes; convert to MB/GB for user display. Calculate total storage needed: 1 million 256KB images = how many GB?
API Payload Sizing
Know that a 3 MB JSON payload becomes ~4 MB after Base64 encoding for transmission—important for API size limits.
CSS Responsive Design
Design at 16px base font size; convert pixel values to rem for scalable layouts (48px heading = 3rem).
Log Analysis
API timeout set to 30000ms—that's 30 seconds in human terms.
Performance Budgets
Mobile page should load in under 3 seconds on 3G (typical 3G = 3 Mbps = 375 KB/s); calculate max initial bundle size.
Limitations & Important Notes
The tool uses standard conversion factors but real-world performance may vary. Network speeds depend on latency, packet loss, protocol overhead (TCP/IP headers add ~5-10% overhead not included in calculations). Storage manufacturer specs (SI mode) differ from OS reporting (IEC mode)—a '1 TB' disk shows as ~931 GB in Windows. Time conversions assume standard definitions (not accounting for leap seconds or calendar complexities). CSS unit conversions assume browser default 16px root font size unless you specify otherwise. The Base64 calculator shows theoretical 33% overhead; actual overhead includes line breaks if wrapping is enabled. For financial or scientific precision, verify conversions with domain-specific tools. The tool is for quick developer estimates, not engineering specifications requiring high precision.