RAM True Latency Calculator

CAS Latency (CL) alone doesn't tell you real-world speed — it has to be read alongside the data rate. This calculator converts both into the actual first-word access time in nanoseconds, using the standard JEDEC memory timing formula.

RAM True Latency Calculator

Enter your own kit's CAS Latency and data rate (from the spec sheet or box) — this uses the standard JEDEC timing formula, not a claim about any specific product.

12.00 ns

true first-word latency

Formula: (CL ÷ (data rate ÷ 2)) × 1000. Lower ns generally means faster real-world response — a higher CL number at a higher data rate can still land at a similar or better ns value than a lower CL at a lower data rate.

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Why CL numbers alone are misleading

A CL36 kit at DDR5-6000 and a CL30 kit at DDR5-5000 both work out to the same 12ns true latency — the CL number by itself, without the data rate, doesn't tell you which kit actually responds faster. Full buying criteria in our RAM buying guide.