Percentage Calculator

Comprehensive Percentage Calculator

Compute core percentage proportions, calculate sales tax, tips & markups, and solve reverse percentages to find original values

Rate or share percentage
Reference whole amount
Calculated Result
30.00
20% of 150
Fractional Ratio: 3/10 • Decimal: 0.200
Primary Calculated Value 30.00 Direct proportional output
Remaining Balance (100% – X%) 120.00 80% of reference base
Decimal Proportion Factor 0.2000 Multiplier equivalence
Simplified Ratio 1 : 5 Reduced fractional share
Base starting value
Tax, tip or discount rate
Final Total After Addition
102.00
Total with +20% Added
Adjustment Amount: +17.00 (1.200× Multiplier)
Final Resulting Total 102.00 Base ± Adjustment
Adjustment Amount (Delta) +17.00 Tax / discount cash amount
Compound Multiplier 1.2000× Direct scaling factor
Effective Ratio Check 6 : 5 Final vs Initial ratio
Total after tax or discount
Tax or discount rate applied
Recovered Original Base Value
100.00
Original Pre-Tax Value
Implied Tax/Discount Amount: 20.00 (÷ 1.200 Multiplier)
Original Base Value (P₀) 100.00 Pre-adjustment baseline
Extracted Difference 20.00 Difference from final total
Inverse Divisor Factor 1.2000 1 ± (Rate / 100)
Verification Check 120.00 Original recalculated to final