How does the percent key work?

200 + 10% gives 220, because the ten percent is taken OF everything to its left rather than added as the bare number 0.1. Subtraction works the same way, so 200 - 10% gives 180, and percentages chain: 200 + 10% + 5% reaches 231, because the second percentage is taken of 220. A percentage on its own is still a plain fraction, so 50% is 0.5, and multiplying or dividing is unchanged: 200 x 10% is 20 and 200 / 10% is 2000. This is CalcTrail’s own rule for the percent key.

Can I keep calculating with the tape total?

Yes. Switch on Show Overall Total in the tape controls and the total appears at the foot of the tape, rounded to 15 significant digits as each line is. Its button sends it to the display: after an operator it is the next number, and after a number it is multiplied in, as MR is.

Can I subtotal part of the tape?

Yes, search first. Type a word into the tape search box and the tape narrows to the lines that match it, in the expression, the result, a tag, or a note. With Show Overall Total on, the label changes to TOTAL (filtered) and it sums only those lines. Tag entries "fuel" or "materials" in Tape view, with Tags & Notes ticked, and searching for one gives you that group's subtotal without disturbing the rest of the tape. Clear the search and the overall total comes back. That suits bookkeeping and simple accounting checks, where you need to keep track of what each line was for.

Can I correct a line on the tape?

Yes. In List view, press the pencil on any line, edit the expression, then press Enter or Save and that line recomputes with the same evaluator the keypad uses, so an edited line always agrees with a typed one. Only the line you edited changes, because each line here is its own calculation, with no running total to redo. Any tag or note you attached moves with the line, and Escape abandons the edit.

How do I use the memory functions (M+, M-, MR, MC)?

M+ works out the calculation in progress and adds its result to memory, and M- subtracts it, so 100 - 25 then M+ stores 75. MR (Memory Recall) puts the stored number into your calculation, as the next number after an operator or multiplied in after a number, and MC (Memory Clear) resets memory to zero.

Does this calculator follow order of operations?

Yes. Brackets come first, then powers from right to left, then multiplication and division, then addition and subtraction, each pair left to right. A minus sign in front of a number applies after the power, so -2^2 is -4. Use brackets to change the order. This is the order taught as PEMDAS in the US and BODMAS in the UK.

How does the tape history work?

The tape records each calculation like a receipt; tick Include Time to show when each was made. You can search long sessions by expression, result, tag or note, correct any line in place from List view, and switch between list and tape views. Tags and notes are saved with the tab, and with Tags & Notes ticked they travel into the printed tape and the export. In Tape view, Print tape opens a printable copy of the tape, with the total if Show Overall Total is ticked and the times, tags and notes if you switched them on, as a printing calculator would print it.

What is the difference between List and Tape view?

List view shows each calculation as a separate, searchable entry (newest first), which suits reviewing or reusing past results. Tape view lays your calculations out like a printed receipt (oldest first), with a total at the foot when Show Overall Total is ticked. That makes it an adding machine for totalling a series of numbers such as expenses, a bill, or an invoice. Switch between them with the View toggle above the history.

Can I use keyboard shortcuts?

Yes. Use standard keyboard keys: number, operator and bracket keys for input, Enter for '=', A for 'Clear' (AC), and Backspace for 'Delete'. Esc closes the calculator tab, as it does across the app. To copy a result, use the Copy button in the header. The Copy button puts the result on your clipboard, and each line in List view has its own copy button, so a figure can be pasted into a spreadsheet, an email or a document.

Is this calculator free to use?

Yes, this basic online calculator is free. It works on any device with a web browser. If you sign in, your calculation history and settings sync to the cloud so you can switch between devices.

Online Calculator with Tape - History & Memory Keys

Formulas and sources

Each formula this calculator uses, where it comes from, and what it leaves out.

Order of operations

Brackets come first, with the number inside sin, cos, tan or √. Next come powers (^), right to left, so 2^3^2 is 2^9 = 512. A minus sign in front of a number applies after a power on its right, so -2^2 is -4 and (-2)^2 is 4; spreadsheets such as Excel read -2^2 as 4. A negative result or recalled number goes in brackets first, so it is raised as a whole. Multiplication and division follow, left to right, and a number next to a bracket is multiplied at this step, so 6÷2(1+2) is 9. Addition and subtraction come last, left to right. A bracket left open at = is closed for you.

Source: The conventional order, as the Common Core State Standards for Mathematics name it in 6.EE.A.2.c [1]; each pair left to right, as the Progressions explain it [2]. The leading minus follows written algebra; no standard states it. Implicit multiplication: CalcTrail’s own; no publisher.

Percent key (%)

On its own, or after × or ÷, B% is B ÷ 100, so 200 × 10% is 20 and 200 ÷ 10% is 2,000. After + or −, B% is B percent of everything to its left, so 200 + 10% is 220 and 200 + 10% + 5% is 231. The % key needs a plain number before it, so (5+5)% is refused.

Source: A percent as a rate per 100: Common Core State Standards for Mathematics, 6.RP.A.3.c [1]. The add-on reading after + or −: CalcTrail’s own rule; no publisher.

Sci row: sin, cos, tan, √, xʸ and π

Result = sin(X × π ÷ 180)

X: the angle, in degrees

cos and tan work as sin does; angles are in degrees only. tan has no answer at 90°, 270° and every 180° from them, and √ needs a number of 0 or more. π is 3.141592653589793, and it cannot be stored exactly, so sin(180) shows 1.225e-16 rather than 0.

Source: The degree as NIST defines it, 1° = π/180 rad [3]. The functions and π as the NIST Digital Library of Mathematical Functions defines them [4] [5], computed as ECMA-262 allows [6].

Errors

A division by zero shows Error with a message that division by zero is not allowed. That covers 0 ÷ 0 and a divisor that works out to zero, such as (1 − 1). A square root of a negative number and tan(90°) have no real answer, and a result too large to hold is refused. An error never goes on the tape.

Source: Division by zero is undefined: standard rule; no single publisher. The messages are CalcTrail’s own.

Rounding and display

Each result is rounded to 15 significant digits, and that is what the tape keeps. The display adds no padding zeros: up to two decimals from 1 up, so 2 + 3 shows 5, and up to ten significant digits below 1, so 1 ÷ 3 shows 0.3333333333. From 10^15 up and from 10^-9 down, results show in exponential form with up to three decimals, so 10^16 shows 1e+16.

Source: CalcTrail’s own display rules; no publisher.

Memory keys

M+ works out the calculation in progress and adds its result to memory; M− subtracts it. MR puts the stored number into your entry: after an operator it is the next number, and after a number it is multiplied in. MC clears memory; AC does not.

Source: CalcTrail’s own; no publisher.

Tape total

With Show Overall Total ticked

The total is the sum of the results of the lines on screen, so a search gives a subtotal. It is rounded to 15 significant digits, as each line is: lines of 0.1 and 0.2 total 0.3.

Source: Standard formula; no single publisher.

Sources

National Governors Association Center for Best Practices and Council of Chief State School Officers. Common Core State Standards for Mathematics, standards 6.EE.A.2.c (order of operations) and 6.RP.A.3.c (percent). 2010.
Common Core Standards Writing Team. Progressions for the Common Core State Standards for Mathematics, Expressions and Equations, grades 6 to 8, p. 176. Institute for Mathematics and Education, University of Arizona, February 28, 2023.
National Institute of Standards and Technology. NIST Guide to the SI, Chapter 5: Units Outside the SI, Table 6, the degree. Special Publication 811 (2008), web page updated December 8, 2025.
National Institute of Standards and Technology. NIST Digital Library of Mathematical Functions, §4.14, sine, cosine and tangent, and §4.23, their inverses. Release 1.2.8, September 15, 2026.
National Institute of Standards and Technology. NIST Digital Library of Mathematical Functions, §3.12, π (3.12.1) and e (3.12.3). Release 1.2.8, September 15, 2026.
Ecma International, TC39. ECMAScript Language Specification (ECMA-262), §21.3.2, Function Properties of the Math Object, the note. Living standard, titled ECMAScript 2027, read October 4, 2026.

What this calculator does not cover

Degrees only, with sin, cos, tan, √, xʸ and π. It has no e, log, factorial, constants or angle setting; the Scientific Calculator has them.
Real numbers, one expression at a time, to 15 significant digits. The keypad cannot put a minus straight after ×, ÷ or xʸ; use ± or a bracket.
The tape keeps the last 100 lines.

Sources checked on October 6, 2026.

Help

Enter your expression: Type numbers and operators, or click the keypad.
Get your result: Press = or Enter to calculate.
Switch tape or list view: Toggle between a receipt-style tape with a running total, and a compact list.
Use memory keys: M+ to store, M− to subtract, MR to recall, and MC to clear.
Search or annotate the tape: Filter past entries, or add tags and notes before printing.
Export or print your history: In Tape view, download the tape as JSON, CSV or a branded PDF, or print it directly.

Understanding the Tape Calculator

How the tape works

The keypad works like any simple calculator: type a calculation and press equals. The result is saved to the History & Tape panel next to the keypad (below it on a phone), so nothing scrolls out of sight. It keeps a running record of your last 100 results, which you can search, reuse, print, or export.

List view vs Tape view: which to use

List view shows each calculation as its own entry, newest first. It suits looking back at, searching, or reusing a past result. Tape view lays them out like a printed receipt, oldest first, and with Show Overall Total ticked it sums them at the foot. That makes it an adding machine for totalling a series of numbers such as expenses, a bill, or an invoice. Switch with the View toggle above the history. Tape view reads like the paper tape of an adding machine: the oldest line comes first and, with Show Overall Total ticked, the total sits at the foot.

Order of operations

It works in the conventional order: brackets, powers, multiplication and division, then addition and subtraction, each pair left to right. So 2 + 3 × 4 is 14, not 20. Wrap part of an expression in brackets to work it out first: (2 + 3) × 4 is 20.

How the percent key works

After + or −, the % key takes that percent of everything to its left: 200 + 10% gives 220 and 200 − 10% gives 180. Adding a tax or tip is one step. After × or ÷, or on its own, a percent is a hundredth: 200 × 10% is 20, and 50% is 0.5.

Memory keys

Memory holds a number while you work out another. M+ adds the result on the display to it and M− subtracts it; MR brings it back and MC clears it. An "M" marker appears on the display whenever something is stored.

Keyboard shortcuts

You can type instead of clicking: number, operator and bracket keys work as expected, Enter is equals, A clears (AC), and Backspace deletes the last digit. Esc closes the calculator tab, as it does across the app. Use the Copy button in the header to copy the result.

Online Calculator with Tape - History & Memory Keys

Formulas and sources

Order of operations

Percent key (%)

Sci row: sin, cos, tan, √, xʸ and π

Errors

Rounding and display

Memory keys

Tape total

Sources

What this calculator does not cover

Help

Understanding the Tape Calculator

How the tape works

List view vs Tape view: which to use

Order of operations

How the percent key works

Memory keys

Keyboard shortcuts

Frequently Asked Questions

Related Calculators

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Online Calculator with Tape - History & Memory Keys

Formulas and sources

Order of operations

Percent key (%)

Sci row: sin, cos, tan, √, xʸ and π

Errors

Rounding and display

Memory keys

Tape total

Sources

What this calculator does not cover

Help

Quick Start Guide

Understanding the Tape Calculator

How the tape works

List view vs Tape view: which to use

Order of operations

How the percent key works

Memory keys

Keyboard shortcuts

Features

Example

Frequently Asked Questions

Related Calculators

Scientific Calculator

RPN Calculator

Fraction Calculator

Percentage Calculator

Unit Converter

Ratio Calculator