Instant 5G Throughput Calculator
Estimate peak and net downlink throughput for NR using bandwidth, numerology, modulation, coding, and MIMO layers.
What this 5G throughput calculator does
This tool estimates 5G NR downlink throughput from core physical-layer parameters. It is designed for quick engineering checks, link budget sanity checks, and planning conversations where you need a realistic estimate rather than a perfect scheduler-level simulation.
The calculator outputs both a raw PHY estimate and a net user-rate estimate after accounting for overhead and downlink time allocation. In other words, it helps bridge the gap between textbook peak rates and what users might actually experience.
Throughput formula used
The calculator uses the following model:
- Bits per slot = RBs × 12 subcarriers × data symbols/slot × modulation bits × code rate × MIMO layers
- Slots per second = 1000 × (SCS / 15)
- Raw throughput (bps) = bits per slot × slots per second
- Net throughput (bps) = raw throughput × (1 − overhead) × DL allocation
This aligns with the common NR frame structure intuition: higher numerology increases slot rate, and higher modulation/coding/layers increase bits carried in each slot.
How to choose each input
1) Bandwidth and RBs
If you already know the active NRB (resource block) count, enter it directly for the best result. If not, leave RB blank and the calculator will estimate it from bandwidth and SCS (using standard values when available).
2) Modulation and coding rate
Higher SINR allows stronger MCS values, which usually means higher modulation (64QAM/256QAM) and higher coding rate. For conservative planning, use 16QAM or 64QAM with moderate coding.
3) MIMO layers
Layers represent spatial streams. Real-world layer usage depends on UE capability, antenna configuration, channel quality, and scheduler policy. Peak marketing rates often assume ideal multi-layer operation.
4) Overhead and DL allocation
Overhead captures control channels, pilots, signaling, and implementation effects. DL allocation is especially important in TDD systems where downlink does not occupy all slots.
Example scenario
Suppose you model a 100 MHz carrier at 30 kHz SCS, 64QAM, coding rate 0.89, 4 layers, 12 data symbols, 14% overhead, and full DL time allocation. You should see a high theoretical value, then a noticeably lower net value after overhead. That difference is expected and useful when explaining KPI expectations to non-RAN stakeholders.
What this calculator does not include
- Detailed scheduler behavior (per-UE grants, fairness, QoS policy)
- CQI dynamics and HARQ retransmission effects over time
- Inter-cell interference variation and mobility effects
- Carrier aggregation and dual connectivity aggregation logic
- Full uplink throughput modeling
For certification-grade analysis, use a full 3GPP-aligned system simulator. For quick sizing, this calculator is a strong starting point.
Frequently asked questions
Is this peak throughput or user throughput?
It reports both raw PHY and net estimate. Net estimate is closer to user throughput, but still simplified.
Why does changing SCS affect throughput?
Larger subcarrier spacing shortens slot duration, increasing slots per second. This can raise raw throughput in the model.
Can I use this for mmWave?
Yes for rough calculations. Just verify realistic RB counts, overhead, and DL/UL split for your deployment.
Final thoughts
A good 5G throughput estimate is not just about one formula. It is about selecting assumptions that match your network reality. Use this calculator to quickly test scenarios, compare configurations, and make more grounded performance decisions.