Quick wins for a faster PC:
Repair Windows errors before they cause bigger problemsFix Now →Fix the driver behind crashes, sound loss and screen glitchesFind Drivers →Clear out junk files and repair common Windows errorsFree Scan →Choose an online calculator by the job you need done: percentages, splitting a restaurant bill, estimating a sale total, comparing package sizes, estimating a loan payment, or converting units. The six functions below cover those everyday tasks; each result depends on the inputs and assumptions you provide.
1. Percentage calculator
Use a percentage calculator to answer three common questions: What is a percentage of an amount? What percentage is one value of another? How much did a value increase or decrease in percentage terms? Calclumo and Calci list these percentage tasks, and Callculus describes a percentage tool for discounts and changes.
As an Amazon Associate I earn from qualifying purchases.
For a change calculation, enter the starting and ending values in the fields the tool provides. Check which value it treats as the original, since percentage change is measured relative to the starting value.
2. Tip and bill-split calculator
A tip calculator can estimate a tip from the bill and rate you enter; a split-bill function can divide the resulting total among diners. Calclumo and Calci list tools for tipping and splitting restaurant bills.
#1 Best Overall
- Fundamental, two-line calculator that combines statistics and advanced scientific functions for high school math and science
- Two-line display shows the entry and calculated result at the same time for easy understanding of the calculation
- Fraction features, conversions, and basic scientific and trigonometric functions
- Solar and battery powered
- Approved for use on SAT, ACT and AP exams
Before using the per-person result, check whether the tip is included in the amount being split and whether the bill should be divided evenly. The output follows the bill basis and tip rate you enter.
3. Discount and tax calculator
For a sale purchase, enter the original price and discount rate to estimate the reduced price. A tax function can add or remove a supplied sales-tax or VAT rate. Calclumo and Calci list discount and tax calculators.
Treat the result as an estimate based on your entries, not a guaranteed checkout total. Tax rates and rules depend on location, and the amount charged may differ from a simple calculation using one rate.
Outdated Drivers Are Slowing You Down
One free scan finds every outdated or missing driver and matches the right update for your exact hardware.Free scan · exact hardware matchPC Slower Than It Used to Be?
A free scan shows the junk files, broken settings and background clutter dragging Windows down - then fixes them in one click.Free scan · Windows 10 & 11Rank #2
- Makes understanding math and science topics quicker and easier — ideal for middle school through college
- Built-in MathPrint feature allows you to input and view math symbols, formulas and stacked fractions exactly as they appear in textbooks
- Graph in vibrant colors to make faster, stronger connections. Powered by a TI Rechargeable Battery that can last up to one month on a single charge.
- 4-year subscription for the TI-84 Plus CE online calculator included with purchase
- Lightweight yet durable enough to withstand the demands of the classroom year after year
4. Unit-price calculator
To decide which package is the better buy, compare cost per unit rather than the shelf price alone. Calci lists a unit-price comparison calculator. Enter each package’s price and quantity, then compare both using the same unit, such as cost per ounce or cost per 100 grams.
A lower unit price is useful only if you can use the quantity before it goes to waste. Check that the package quantities and units are comparable before choosing.
5. Loan-payment calculator
A loan calculator can estimate a periodic payment and total interest from the principal, interest rate, and term you enter. Calclumo describes its loan calculator as estimating monthly payments and total interest using amortization; Callculus lists monthly-payment and interest outputs.
Rank #3
- View multiple calculations at the same time: Compare results and explore patterns on-screen with the MultiView display that supports up to four lines
- See math exactly as it appears in textbooks: Display math expressions, symbols and stacked fractions exactly the way they appear in textbooks — no need to adapt to a technical syntax; provides quick access to frequently used functions
- Scientific notation output: View scientific notation with the proper superscripted exponents and see the output in scientific notation
- Explore (x,y) table of values: Students can easily explore an (x,y) table of values for a given function automatically or by entering specific x values
- The TI-30XS MultiView scientific calculator is ideal for general math, Pre-Algebra, Algebra 1 and 2, Geometry, Statistics, general science, Biology and Chemistry
Use the result as an estimate, not a lender quote. Fees, lender-specific terms, and rate conventions can change the amount due. Verify consequential figures against the lender’s offer and terms.
6. Unit converter
A unit converter helps translate everyday measurements such as length, weight, or temperature. Calclumo lists dedicated converters, and Callculus lists a unit converter.
Confirm the starting and target units before using the converted value. A number without its unit can be misleading, especially when copying a result into a recipe, travel plan, or measurement.
Rank #4
- Ideal for curricula in which graphing technology may not be permitted.
- MultiView display shows multiple calculations at the same time on screen.
- MathPrint shows math expressions, symbols and stacked fractions as they appear in textbooks
- Ideal for high school through college: Algebra 1 & 2, Geometry, Trigonometry, Statistics, Calculus, Biology, etc.
- Convert fractions, decimals and terms including Pi into alternate representations.
How to choose an online calculator
Start with the calculation you need, then check whether the tool supports the required inputs and makes its assumptions understandable. Useful comparison points include:
- Task coverage: Does it handle the exact calculation, such as percentage change rather than only a percentage of a number?
- Formula clarity: Does it explain how it derives the result or provide a worked example?
- Input flexibility: Can you enter the values and units you actually have?
- Regional assumptions: Does it let you supply the relevant currency or tax rate?
- Mobile usability: Can you enter values and read the result comfortably on your device?
Calclumo says its calculators explain formulas and include worked examples; Calci lists its available functions. These are provider descriptions, not results from a standardized or independent comparison, so they do not establish that one service is best overall.
Do these 3 things before closing this tab:
1Clear out junk files and repair common Windows errors2Fix the driver behind crashes, sound loss and screen glitches3Repair Windows errors before they cause bigger problemsAccuracy and privacy: what to check
For tips, taxes, shopping comparisons, and loan estimates, the answer is only as useful as the inputs and assumptions. Check your entries, and verify important amounts against the relevant bill, retailer, lender, or local rules.
Calclumo says calculations run in the browser and entered values stay on the device. That is the provider’s privacy claim, not an independently audited finding; it should not be assumed to apply to other calculator sites. The reviewed provider pages describe calculator functions but do not independently certify their accuracy.
Further practice with everyday money math
The NWT Literacy Council’s Money Math: Everyday Math Skills is a 2009 workbook with exercises on compound interest, tipping, discounts, and costs. It is an optional learning resource, not a requirement for using an online calculator.
Quick Recap
Product prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on Amazon at the time of purchase will apply.
What’s actually slowing this PC down?
Pick the symptom - the matching free tool is one click away.
