Overview
Choose bill amount, tip percent, and party size. Remember local customs and whether service is included.
How to use this calculator
Adjust inputs to mirror your real-world cadence. The calculator applies standard formulas described in the Formula section—always verify critical figures independently.
Formula and methodology
Outputs derive from established formulas implemented in code for repeatability. Units must stay consistent across fields.
When to use this calculator
Planning
Estimate outcomes before negotiating or committing.
Comparison
Contrast two interest rates or terms side by side.
Education
Teach amortisation intuition with transparent formulas.
Common mistakes
Unit mismatch
Mixing monthly payments with annual rates without aligning periods.
Percent vs decimal
Entering 6 instead of 0.06 when the field expects decimal form.
Ignoring fees
Forgetting taxes, insurance, or fees that change net cash flows.
Key terms
Principal
Original amount borrowed or invested before interest.
APR
Annual percentage rate—often quoted for loans; verify compounding assumptions.
Compounding
Frequency at which interest is calculated and added to balance.
Amortisation
Process of paying down principal over scheduled payments.
References and further reading
Related calculators
FAQ
Professional advice?
Why results differ elsewhere?
Regulated medical or legal use?
Currency?
Taxes?
Precision?
Kids vs adults?
Can I embed assumptions?
Results are estimates for educational purposes and may not match your exact situation.