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Primer Tm Calculator

Calculate Melting Temperature and GC Content for PCR Primers

Basic Tm Formula

Tm = 4(G + C) + 2(A + T)

This simple formula provides a quick estimate of primer melting temperature. For primers 18-24 bp in length, this gives a reasonable approximation for initial PCR design.

Note: For more accurate Tm calculations (especially for longer primers or those with modified bases), use specialized software like Primer3 or IDT's OligoAnalyzer.

Length: 0 bp
Melting Temp (Tm)
-
°C
GC Content
-
%
Primer Length
-
bp

Base Composition

A
0
T
0
G
0
C
0