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SSL/TLS Overhead Calculator

Calculate SSL/TLS handshake performance impact and CPU cost

Number of new TLS connections established per second. Each requires a handshake.
conn/sec
TLS 1.3 requires fewer round trips (1-RTT vs 2-RTT) and has more efficient handshake.
RSA key exchange is CPU-heavy. ECDHE is faster. Cipher choice affects CPU cost per handshake.
Percentage of connections that reuse previous session (0-RTT or abbreviated handshake). Reduces overhead significantly.
%
ms

Results

Full Handshake Round TripsRTT
Avg Handshake Time (full)ms
Effective Connection Rateconn/sec
CPU Cost Estimatecore-% utilization
Handshake BandwidthMbps
Connection Setup Time (avg)ms
How it works: TLS 1.3 reduces handshake to 1-RTT (vs 2-RTT for TLS 1.2). Session resumption avoids full key exchange. CPU cost varies by cipher: RSA is ~10x more expensive than ECDHE. Handshake bandwidth = connections × handshake data size.