Bandwidth Calculator
Calculation Mode
Calculate Transfer Time
Calculate File Size
Calculate Required Speed
Unit Converter
💡 Note: 1 Byte = 8 bits. ISPs typically advertise in Mbps (megabits), while file sizes are shown in MB (megabytes). Divide Mbps by 8 to get MB/s download speed.
📶 Common Speeds
Dial-up56 Kbps
DSL1–100 Mbps
Cable10–500 Mbps
Fiber100 Mbps–10 Gbps
Wi-Fi 5 (ac)up to 3.5 Gbps
Wi-Fi 6 (ax)up to 9.6 Gbps
5G Mobileup to 10 Gbps
Ethernet 1G1 Gbps
Ethernet 10G10 Gbps
Select a calculation mode, enter your values on the left, and click Calculate.
📋 Calculation Results
📋 Detailed Breakdown
🔄 Data Size — All Unit Conversions
| Unit | SI (decimal) | IEC (binary) |
|---|
🔄 Speed — All Unit Conversions
| Unit | Value | Notes |
|---|
📈 Transfer Time at Different Speeds
🖥 Common File Sizes Transfer Time
📶 Real-World Speed Equivalents
📖 Bandwidth Unit Reference
| Unit | Symbol | Bits | Notes |
|---|---|---|---|
| Bit | b | 1 | Smallest unit |
| Kilobit | Kb | 1,000 | SI decimal |
| Megabit | Mb | 1,000,000 | SI decimal — ISP speeds |
| Gigabit | Gb | 1,000,000,000 | SI decimal |
| Byte | B | 8 | 8 bits = 1 Byte |
| Kilobyte | KB | 8,000 | SI decimal |
| Megabyte | MB | 8,000,000 | SI decimal — file sizes |
| Gigabyte | GB | 8,000,000,000 | SI decimal |
| Kibibyte | KiB | 8,192 | IEC binary (2¹⁰) |
| Mebibyte | MiB | 8,388,608 | IEC binary (2²⁰) |
| Gibibyte | GiB | 8,589,934,592 | IEC binary (2³⁰) |
💡 Bandwidth Tips & Formulas
📐 Key Formulas:
• Transfer Time = File Size (bits) ÷ Bandwidth (bps)
• File Size = Bandwidth (bps) × Time (seconds)
• Required Speed = File Size (bits) ÷ Time (seconds)
⚠ ISP vs. Real Speed:
ISPs advertise in Megabits per second (Mbps). Your download manager shows Megabytes per second (MB/s). Divide Mbps by 8 to get MB/s.
📶 Overhead factors:
• TCP/IP headers add ~3–5% overhead
• Wi-Fi has ~10–15% overhead due to collision avoidance
• VPNs add ~10–30% encryption overhead
• Satellite links have ~500–600ms latency
📊 Real-World Efficiency:
Theoretical speeds are never achieved. Expect 70–95% of advertised speeds under ideal conditions, and 40–70% in busy/congested networks.
• Transfer Time = File Size (bits) ÷ Bandwidth (bps)
• File Size = Bandwidth (bps) × Time (seconds)
• Required Speed = File Size (bits) ÷ Time (seconds)
⚠ ISP vs. Real Speed:
ISPs advertise in Megabits per second (Mbps). Your download manager shows Megabytes per second (MB/s). Divide Mbps by 8 to get MB/s.
📶 Overhead factors:
• TCP/IP headers add ~3–5% overhead
• Wi-Fi has ~10–15% overhead due to collision avoidance
• VPNs add ~10–30% encryption overhead
• Satellite links have ~500–600ms latency
📊 Real-World Efficiency:
Theoretical speeds are never achieved. Expect 70–95% of advertised speeds under ideal conditions, and 40–70% in busy/congested networks.
🎬 Typical File Size Reference
| File Type | Typical Size | At 100 Mbps |
|---|---|---|
| Email (text) | 20 KB | < 0.01 sec |
| Photo (JPEG) | 3–5 MB | 0.24–0.4 sec |
| MP3 Song | 3–8 MB | 0.24–0.64 sec |
| SD Video (700 MB) | 700 MB | ~56 sec |
| HD Movie (4 GB) | 4 GB | ~5.3 min |
| 4K Movie (50 GB) | 50 GB | ~66.7 min |
| Blu-ray (25 GB) | 25 GB | ~33.3 min |
| Game (70 GB) | 70 GB | ~93.3 min |
| 1 TB Backup | 1 TB | ~22.2 hrs |
