For me, an ideal calculator for miners should be:

Comprehensive: Accept detailed input parameters like hash rate, power consumption, electricity costs, and mining fees.
Accurate: Use real-time data for cryptocurrency prices, network difficulty, and rewards.
Versatile: Support multiple cryptocurrencies and mining algorithms.
Insightful: Provide profitability metrics (daily, monthly, annual earnings) and ROI analysis.
User-Friendly: Feature an intuitive interface for all experience levels.
Educational: Include guides to explain profitability factors and assumptions.
Hardware-Aware: Offer mining hardware comparisons for better decision-making.

These features ensure clear, tailored, and practical insights into mining profitability.