Satellite Delay Calculator
Calculate one-way propagation delay, single-hop RTT, and double-hop round-trip latency for satellite communication links.
1
Inputs
Live
Math
3
Related
Enter parameters and click Calculate to view results
Formula & Theory
t_one_way = d / c, t_RTT = 2 × t_one_way, t_DoubleHop = 4 × t_one_wayThis formula is used to calculate antenna parameters for satellite delay calculator.
Overview
Use this satellite delay calculator to compute electromagnetic propagation delay for satellite communication links across LEO, MEO, and GEO orbits based on slant range.
Input Guide
Enter One-Way Slant Range exactly in the units shown by this satellite delay. Check the operating band, unit prefix, and decimal position before calculating; these are the inputs used by the formula.
- One-Way Slant Range — use km.
Output Guide
The results describe the calculated satellite delay values for the inputs you entered. Check each value against the available space, selected components, feed system, and operating conditions before making a final design decision.
How This Calculator Works
The Satellite Delay uses t_one_way = d / c, t_RTT = 2 × t_one_way, t_DoubleHop = 4 × t_one_way. Supply One-Way Slant Range (km) in the displayed units, then use the calculated values as the first engineering target for this satellite communication design or analysis.
Design Notes
Propagation delay is governed by the speed of light (~299,792.458 km/s). GEO satellites (~38,000 km slant range) introduce an unavoidable minimum one-way delay of ~127 ms (250+ ms single-hop RTT), whereas LEO satellites (~550 km) achieve single-digit millisecond propagation delays.
Build and Tuning Notes
A standard single-hop internet connection involves 4 space passes: Ground Station → Satellite → Earth Terminal → Satellite → Ground Station (double-hop latency). Factor in modem processing and terrestrial backhaul (~10–30 ms) for total end-to-end ping.
Frequently Asked Questions
Why does a GEO satellite connection have a ping around 500–700 ms?
A complete request-and-response cycle over GEO involves four space propagation paths (2x uplink + 2x downlink = ~500 ms propagation) plus ground station routing, processing, and terrestrial internet backhaul.
How much latency does a LEO satellite network like Starlink add?
At a 550 km altitude, one-way space propagation takes ~1.8 to 4 ms (depending on elevation angle). Total end-to-end RTT including ground routing typically ranges from 25 to 45 ms.
What is the speed of light used for RF propagation calculations?
RF signals travel through free space at the speed of light, c ≈ 299,792.458 km/s (or ~3.33 microseconds per kilometer).
Alex Warren
B.Sc. in Electrical & Electronic Engineering (EEE)
Alex specialises in antenna design and wave propagation. His expertise helps ensure these calculators present practical RF concepts, useful design estimates, and clear engineering guidance for students, HAM operators, and wireless professionals.