# CalcTrail > CalcTrail (https://calctrail.com) is a free set of calculators and converters for finance, health, engineering, AI costs, marketing, design, grades, dates and times, and everyday math. Calculations run in your browser, no account is needed, and we do not sell user data. **Key features** - **Runs in your browser:** All calculations run in your browser. We do not sell user data. - **Data Saving:** Signed in, your workspaces, tabs, history, variables and settings are saved to your account and available on any device. As a guest, they stay in this browser; a share link sends just that one calculation to us. - **Workspaces:** Keep each project in its own workspace, with its own tabs and history. Custom variables are shared across all workspaces. - **History:** Save the calculations you want to keep, tag and filter them, restore any entry, and export a workspace's history as JSON. - **Custom Variables:** Save a value you reuse, such as a tax rate or an hourly rate, and insert it into any field that shows the variable icon. A numeric variable can record its unit (kΩ, $/mo, kcal), chosen from a fixed list; creating one from a field copies its number, and its unit where the field has one. - **Global Search:** Press Cmd/Ctrl+K to search calculators, saved history, variables and workspaces. It matches tool names and other common names for them ("gratuity" finds the Tip Calculator), tolerates a missing letter, and runs commands (type > for actions like >theme dark). - **Quick Calc:** Most number fields open a small calculator in the same panel, for working out a figure you do not have yet and putting the answer straight into the field. - **Multi-Tab Interface:** Keep several calculators open in tabs, each with its own inputs and undo/redo history; only the tab on screen is running. Most number fields can pull the inputs and results of another open tab, and beside a result the copy button can send that number the other way — into an open tab's field, or into a calculator opened for it — so a figure worked out in one calculator is never retyped in another. On calculators that have it, "Continue in another calculator" at the end of the result panel hands a whole set of entries to a calculator that carries on from them. - **Export & Import:** Every calculator exports as JSON, CSV or a branded PDF, with no account required. Signed out, long tables stop at the first 10 rows, with a note; a free account exports every row (full amortization schedules, full comparisons, the full tape or session from the keypad calculators). Custom variables can be imported from CSV with a free account; history cannot be imported. - **Shareable Links:** Share one calculation as a view-only link that anyone can open without an account. It is a copy, so your later edits do not reach it unless you share the tab again, and it expires after 7, 15 or 30 days. - **Keyboard Shortcuts:** Shortcuts for search (Cmd/Ctrl+K), saving (Cmd/Ctrl+S), undo and redo, and switching tabs (Cmd/Ctrl+1-9); press ? for the full list. - **Accessibility:** Controls are labelled for screen readers, and heading order, control names and colour contrast (against the WCAG AA minimum) are checked with automated audits. That is what is tested, not a certification. - **Appearance:** Light, dark or system theme, plus interface density and font size. **Usage tips** - **Tape History:** The keypad calculators log each calculation as you go and keep your recent lines — a running tape on Basic, a session list on RPN and Scientific. Saving the Basic calculator to your history keeps its whole tape as one entry you can restore, tag and export. - **Export:** Download any result as JSON, CSV or PDF without an account; signing in adds the complete multi-row tables. - **Import:** Bring in custom variables from a CSV file (free account). History is not importable — Settings → Plan & Data restores a full backup. - **Shortcuts:** Cmd/Ctrl+K opens search, Cmd/Ctrl+S saves, and Esc closes the current tab. On the keypad calculators, Enter calculates (on RPN it pushes to the stack) and Backspace deletes. Press ? for the full list. - **Workspaces:** Organize calculations into separate workspaces (e.g., "Work Projects", "Personal Finance") with independent history and tabs. - **Custom Variables:** Create reusable variables (e.g., `tax_rate`, `monthly_income`) and insert them into any field that shows the variable icon, in any calculator. - **Global Search:** Type a calculator name or another name for it — "loan", "amortization", "gratuity". A missing letter is tolerated, so "morgage" still finds the Mortgage Calculator. - **Related Calculators:** Every calculator lists related calculators at the bottom of its page. - **Examples & Quick Start:** Form-based calculators carry worked examples you can load with one click, and every calculator has a Quick Start guide. - **Share Your Work:** Click the Share button in any calculator header to create a link. The link holds a copy of your current calculation; recipients can try other numbers, but nothing they change is saved. **Plan limits** - **Guest Users:** 5 workspaces, 10 tabs per workspace, 50 history entries per workspace, 25 global variables. All data stored locally in browser. - **Free Plan (Logged In):** 10 workspaces, 20 tabs per workspace, 100 history entries per workspace, 100 global variables. Save your data to your account. - **Guests and accounts:** Guests can use every calculator, and workspaces, history, variables and settings, within these limits. A free account adds sync across devices, CSV import of variables, exports with every row of long tables, and deleting share links early. **Privacy and security** - **Encryption:** Connections use HTTPS. Data on our servers (accounts, synced work and share links) is encrypted at rest by Google Cloud SQL. Guest data stays in the visitor's browser. - **Data Control:** Export everything as JSON from Settings → Plan & Data. In its Danger Zone, a guest can reset everything kept in the browser, and a signed-in account can reset its data or delete itself, which removes the account and all its data from our database at once. Email deletion remains for anyone who cannot sign in. - **Your Rights:** CalcTrail is operated from India and follows the Digital Personal Data Protection Act, 2023. It gives everyone the same rights, wherever they live: access, correction, deletion, export, objection, withdrawal of consent and nomination. - **No Data Selling:** We do not sell or rent personal data, and we do not share it with advertisers. - **Analytics (cookieless, one tool):** CalcTrail uses Ahrefs Web Analytics for every visitor, except a visit that starts from a share link (the script is not loaded, so a link's address never reaches it). It sets no cookies, uses no localStorage, and assigns no persistent identifier — unique visitors are counted via a one-way hash of IP + browser + a daily-rotating salt, and the raw IP is discarded. It sees page views and a fixed list of feature events with coarse properties — never calculation values, account details, or search text. There is no cookie banner; visitors can switch analytics off in Settings → Analytics, and Global Privacy Control / Do Not Track signals are honoured. - **Search Queries:** recent searches are kept in the visitor's own browser, signed in or not, and are never sent to our servers. Server-side search storage was retired on 2026-09-03; signed-in users can delete records kept before then in Settings → Search, by turning saving off with the delete option ticked. ## Math & Conversions - [Basic Calculator](https://calctrail.com/calculators/basic-calculator): Arithmetic, tape history, print, memory. - [RPN Calculator](https://calctrail.com/calculators/rpn-calculator): Reverse Polish Notation, stack-based. - [Percentage Calculator](https://calctrail.com/calculators/percentage-calculator): %, change, increase/decrease. - [Unit Converter](https://calctrail.com/converters/unit-converter): 15 categories incl. length, weight, volume, temp, data, energy, fuel economy. - [Fraction Calculator](https://calctrail.com/calculators/fraction-calculator): Add, subtract, multiply, divide, simplify; fraction-decimal conversion. - [Ratio Calculator](https://calctrail.com/calculators/ratio-calculator): Ratios, proportions, scale. - [Scientific Calculator](https://calctrail.com/calculators/scientific-calculator): Trig, hyperbolic, log, exp, powers, roots, factorial, constants. ## Engineering - [Ohm's Law Calculator](https://calctrail.com/calculators/ohms-law-calculator): Calculate voltage, current, resistance, and power. - [Power Calculator](https://calctrail.com/calculators/power-calculator): DC and AC 1-/3-phase power from V, I, R and power factor; energy cost. - [Wire Gauge Calculator](https://calctrail.com/calculators/wire-gauge-calculator): Wire gauge, ampacity, and voltage drop. - [Resistor Color Code](https://calctrail.com/calculators/resistor-color-code-calculator): Decode 4/5/6-band and SMD codes; encode a value to 4/5-band colors. - [Stress & Strain](https://calctrail.com/calculators/stress-strain-calculator): Stress, strain, Young's modulus. - [Beam Deflection](https://calctrail.com/calculators/beam-deflection-calculator): Max deflection, bending moment, reactions and shear/moment diagrams for 4 support types. - [Concrete Volume](https://calctrail.com/calculators/concrete-volume-calculator): Volume for slabs, columns, footings; cement, sand, aggregate, water, bags. - [Pipe Flow](https://calctrail.com/calculators/pipe-flow-calculator): Solve pressure drop, flow rate or pipe diameter; velocity, Reynolds number. - [LC Circuit](https://calctrail.com/calculators/lc-circuit-calculator): Resonant frequency, L or C for a target frequency, and LC/RLC impedance. ## Finance & Business - [Loan Calculator](https://calctrail.com/calculators/loan-calculator): Amortization, refinance, comparison. - [Car Loan](https://calctrail.com/calculators/car-loan-calculator): Payments, trade-in, loan terms. - [Break-Even](https://calctrail.com/calculators/break-even-calculator): Costs vs revenue analysis. - [Markup Margin](https://calctrail.com/calculators/markup-margin-calculator): Profit, cost, price. - [Mortgage](https://calctrail.com/calculators/mortgage-calculator): PITI, affordability, rent vs buy, refinance, stress test, amortization. - [Savings](https://calctrail.com/calculators/savings-calculator): Compound interest, inflation-adjusted value, contribution or time to a goal. - [Investment](https://calctrail.com/calculators/investment-calculator): Future value, required contribution, scenario comparison, Monte Carlo risk. - [Retirement](https://calctrail.com/calculators/retirement-calculator): Nest egg, withdrawal income, readiness score, nest egg needed for a target income. - [DTI](https://calctrail.com/calculators/debt-to-income-ratio-calculator): Debt-to-Income ratio. - [Credit Card Payoff](https://calctrail.com/calculators/credit-card-payoff-calculator): Payoff strategies & interest. - [APY](https://calctrail.com/calculators/apy-calculator): Annual Percentage Yield. - [Payback Period](https://calctrail.com/calculators/payback-period-calculator): Years to recover an investment; uneven cash flows, discounted payback, ROI. - [CD](https://calctrail.com/calculators/cd-calculator): Certificates of Deposit returns. - [401k](https://calctrail.com/calculators/401k-calculator): Growth, employer match, IRS contribution-limit check. - [Roth IRA](https://calctrail.com/calculators/roth-ira-calculator): Growth, limits, eligibility. - [Tip](https://calctrail.com/calculators/tip-calculator): Split bill & gratuity. - [Discount](https://calctrail.com/calculators/discount-calculator): Sale price & savings. - [Sales Tax](https://calctrail.com/calculators/sales-tax-calculator): Price with/without tax. - [VAT](https://calctrail.com/calculators/vat-calculator): Add or remove VAT; multi-line invoices with mixed rates. - [Fuel Cost](https://calctrail.com/calculators/fuel-cost-calculator): Trip fuel cost, per-person split, monthly cost & vehicle comparison. - [Present Value](https://calctrail.com/calculators/present-value-calculator): PV of a lump sum or ordinary annuity, with compounding frequency. - [Unit Price](https://calctrail.com/calculators/unit-price-comparison): Compare deals by price/unit. ## Health & Fitness - [BMI](https://calctrail.com/calculators/bmi-calculator): Body Mass Index, reverse mode. - [Calorie](https://calctrail.com/calculators/calorie-calculator): TDEE, macros, cycling, weight goals. - [TDEE](https://calctrail.com/calculators/tdee-calculator): Total Daily Energy Expenditure. - [Macro](https://calctrail.com/calculators/macro-calculator): Protein, carbs, fat planning. - [Body Fat](https://calctrail.com/calculators/body-fat-calculator): Navy method, body fat %. - [Pace](https://calctrail.com/calculators/pace-calculator): Running pace, finish time or distance; race splits, HR zones. - [Water Intake](https://calctrail.com/calculators/water-intake-calculator): Daily hydration needs. ## Date & Time - [Age](https://calctrail.com/calculators/age-calculator): Years, months, days. - [Date Difference](https://calctrail.com/calculators/date-difference): Days between dates, business days, add/subtract from a date. - [Time Zone](https://calctrail.com/converters/time-zone-converter): Convert & compare world times. - [Time](https://calctrail.com/calculators/time-calculator): Add/subtract durations; time card totals with unpaid breaks. ## Academic - [GPA](https://calctrail.com/calculators/gpa-calculator): 4.0/4.3 scales, credit-weighted GPA, GPA needed for a target. - [Grade](https://calctrail.com/calculators/grade-calculator): Weighted grades, finals. - [Weighted Mean](https://calctrail.com/calculators/weighted-mean-calculator): Weighted averages. ## Design & Creative - [Aspect Ratio](https://calctrail.com/calculators/aspect-ratio-calculator): Image/video dimensions. - [Color Converter](https://calctrail.com/converters/color-converter): HEX, RGB, HSL, color picker; CMYK output. ## Marketing - [ROI](https://calctrail.com/calculators/roi-calculator): Return on Investment. - [ROAS](https://calctrail.com/calculators/roas-calculator): Return on Ad Spend. - [CPM](https://calctrail.com/calculators/cpm-calculator): Cost Per Mille. - [CPC](https://calctrail.com/calculators/cpc-calculator): CPC from cost & clicks or CPM & CTR, max CPC from CPA, budget planning. - [CLV](https://calctrail.com/calculators/clv-calculator): Customer Lifetime Value. - [CAC](https://calctrail.com/calculators/cac-calculator): Customer Acquisition Cost. ## AI & Machine Learning - [LLM Token Cost](https://calctrail.com/calculators/llm-token-cost-calculator): API cost per request and per month across OpenAI, Anthropic, Google and other providers. - [AI ROI](https://calctrail.com/calculators/ai-roi-calculator): ROI and payback period of AI tool subscriptions, from hours saved and hourly rate, with team role benchmarks. - [Token Converter](https://calctrail.com/calculators/token-converter-calculator): Text to token count. - [Image Gen Cost](https://calctrail.com/calculators/image-gen-cost-calculator): GPT Image, Gemini, FLUX, Midjourney costs. - [Speech Cost](https://calctrail.com/calculators/speech-cost-calculator): Speech-to-text/Text-to-speech costs. ## Feature Guides - [Calculation History](https://calctrail.com/features/calculation-history): Look back at the calculations you saved, restore any of them, and keep each workspace’s history separate. - [Workspace Management](https://calctrail.com/features/workspace-management): Give each project, client or subject its own workspace, with its own open tabs and history. - [Global Search](https://calctrail.com/features/global-search): One search box for the calculators and for your own saved work, usable entirely from the keyboard. - [Custom Variables](https://calctrail.com/features/custom-variables): Save a value once and insert it wherever a field shows the variable icon, instead of typing it again. - [Multi-Tab Calculators](https://calctrail.com/features/multi-tab-calculators): Open several calculators in tabs, switch between them, and move numbers from one to another without retyping. - [Save Data](https://calctrail.com/features/save-data): Save your work when signed in and continue where you left off from any device. - [Export PDF & CSV](https://calctrail.com/features/export-pdf-csv): Download any result as JSON, CSV or PDF to keep, print or open in a spreadsheet. - [Shareable Calculations](https://calctrail.com/features/shareable-calculations): Send a calculation to someone as a link they can open without an account. ## Optional - [Full documentation](https://calctrail.com/llms-full.txt): Every tool and feature guide in detail, with the User Guide, About, Privacy Policy and Terms of Service. - [User Guide](https://calctrail.com/guide): How tabs, workspaces, history, variables, search and export work. - [About](https://calctrail.com/about): Who runs CalcTrail and what it covers. - [Updates](https://calctrail.com/updates): Release notes: what changed, and when. - [Privacy Policy](https://calctrail.com/privacy): What is collected, where it is stored, and your rights. - [Terms of Service](https://calctrail.com/terms): The use license, disclaimers and limits of liability.