We have designed, fabricated, and characterized microwave resonators made of granular-aluminum thin films with different oxygen content. The kinetic inductance fraction of these disordered superconductors was determined by electromagnetic finite-element simulations, conformal mapping techniques, and the frequency shift of the resonators with temperature. We compare these methods to assess model-dependent variations and to highlight their main limitations. This analysis aims to guide the community in choosing the most suitable method for designing kinetic inductance detectors, high -mpedance resonators, and superinductors. Additionally, we measured the internal quality factor as a function of microwave power at low temperature to characterize losses, which we identify as arising from two-level systems.

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• Dielectric properties
• Superconducting RF
• Elemental metals
• Elemental superconductors
• Superconducting devices
• Thin films
• Cavity resonators
• Microwave techniques