FRET Calculator | The Shaner Lab

Upload donor emission and acceptor absorbance/extinction spectra, then compute J and R₀.

Example pair (mTurquoise2 donor, mVenus acceptor):

Drag and drop .csv/.xlsx or click to browse

Drag and drop .csv/.xlsx or click to browse

Load spectra, optionally map data columns, then parse to preview.

Donor quantum yield Q_DRefractive index nOrientation factor κ²Acceptor scaling modeAcceptor peak ε_max (M⁻¹ cm⁻¹)

Advanced processing options

InterpolationIntegrationGrid override (nm, optional)Min overlap width (nm)Auto grid min step (nm)Auto grid max step (nm)

Run a calculation to display J, R₀, details, and warnings.

Run a calculation to preview processed spectra.