Decoding electronic structure contributions to resistivity upturn and large magnetoresistance in <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:msub><mml:mi>ZrSn</mml:mi><mml:mn>2</mml:mn></mml:msub></mml:math>

A significant increase in resistance in response to an external magnetic field, often called large magnetoresistance (MR), is a key area of focus in both fundamental solid-state research and modern technological applications. Understanding the interplay between MR, resistivity upturn, and carrier compensation remains complex yet essential in materials with intricate electronic structures. Here, we report the transport properties of a transition metal stannide ${\mathrm{ZrSn}}_{2}$, which exhibits a resistivity upturn and large magnetoresistance (1750% at 2 K and 14 T). We demonstrate that when the ratio of hole to electron concentration is close to unity, the materials display a resistivity upturn under an applied magnetic field. The carrier concentrations estimated from the field-dependent Hall resistivity measurements are nearly compensated, which satisfies the condition necessary for both resistivity upturn and large MR. We also propose a method based on Monte Carlo simulations to calculate the complex Fermi surface volume from first-principles calculation which further reveals carrier compensation in ${\mathrm{ZrSn}}_{2}$.