Free Online Calculators

Every calculator on StudentToolsNG, from CGPA and JAMB scores to percentages, BMI and due dates. All of them are free, work on your phone and show the working.

Why use these calculators

Each calculator shows the formula it uses and a worked example, so you can check the answer and learn the method for exams. Nothing you type is sent to us: the calculations run in your browser.

School and exam calculators

• CGPA Calculator: Work out your university CGPA from your grades and credit units.
• GPA Class of Degree Calculator: See whether your CGPA is First Class, Second Class Upper or Lower.
• CGPA Converter: Convert a 5.0 CGPA to the 4.0 scale and to a percentage.
• JAMB Score Calculator: Add up your four UTME subject scores out of 400.
• Post-UTME Aggregate Calculator: Combine UTME, post-UTME and O'level grades for your university.
• WAEC Grade Calculator: Turn WAEC scores into A1 to F9 grades and count your credits.

Everyday calculators

• Percentage Calculator: Percentages of numbers and money, increases, VAT and discounts.
• BMI Calculator: Body mass index and healthy weight range in kg, cm or feet.
• Ovulation and Period Calculator: Ovulation day, fertile window and next period dates.
• Pregnancy Due Date Calculator: Due date, weeks pregnant and trimester.
• Age Calculator: Exact age in years, months and days, and age on any date.

Engineering and solar calculators

• Ohm's Law Calculator: Voltage, current, resistance and power from any two values.
• Resistor Colour Code: Read 4, 5 and 6-band resistor colours.
• Solar System Calculator: Size panels, inverter and batteries for your load.