All Calculators
Browse our complete collection of 51 free online calculators. Find the right tool for marketing, finance, health, or math.
Marketing Calculators
Free marketing calculators for ROAS, CPC, CPM and more.
Return on Ad Spend Calculator
Calculate ROAS to measure the effectiveness of your advertising campaigns.
Break Even ROAS Calculator
Calculate the minimum ROAS needed to break even on your ad campaigns.
Target ROAS Calculator
Set target ROAS goals and calculate the revenue needed to achieve them.
CPM Calculator
Calculate cost per thousand impressions for your ad campaigns.
CPC Calculator
Calculate cost per click for your paid advertising campaigns.
CTR Calculator
Calculate click-through rate to measure ad engagement.
Conversion Rate Calculator
Calculate conversion rate to measure how many visitors take desired actions.
CAC Calculator
Calculate customer acquisition cost for your marketing channels.
LTV:CAC Ratio Calculator
Calculate the lifetime value to customer acquisition cost ratio.
ROI Calculator
Calculate return on investment for your marketing campaigns.
Marketing Budget Calculator
Plan and allocate your marketing budget across channels.
CPA Calculator
Calculate cost per acquisition for your marketing campaigns.
Customer Retention Calculator
Calculate customer retention rate to measure loyalty.
Churn Rate Calculator
Calculate customer churn rate to understand attrition.
Finance Calculators
Free finance calculators for mortgages, loans, compound interest and more.
Simple Interest Calculator
Calculate simple interest on loans and investments with straightforward linear growth.
Compound Interest Calculator
Calculate compound interest with inflation-adjusted returns. See how your money grows exponentially over time.
Margin & Markup Calculator
Calculate profit margin, markup percentage, and selling price from cost and revenue.
Gross Profit Margin Calculator
Calculate gross profit margin from revenue and COGS with industry benchmarks.
Loan Calculator
Calculate monthly loan payments, total interest, and amortization schedule.
Mortgage Calculator
Calculate monthly mortgage payments, total interest, and affordability.
Savings Goal Calculator
Calculate how much you need to save monthly to reach your financial goals.
Debt Payoff Calculator
Calculate the fastest way to pay off debt with optimized payment strategies.
Investment Return Calculator
Calculate investment returns, compound growth, and total value over time.
Invoice Factoring Calculator
Calculate the true cost of invoice factoring: cash advance, fees, effective APR, and comparison vs a credit line.
SBA Loan Calculator
Calculate SBA 7(a) payments, FY2026 guaranty fees, and check DSCR qualification before you apply.
Cyber Insurance Calculator
Estimate cyber insurance premiums for your SMB, see how security controls cut costs, and size your coverage limit.
Injury Settlement Calculator
Estimate personal injury case value with the multiplier and per-diem methods, then see net payout after attorney fees, liens, and costs.
Health Calculators
Free health calculators for BMR, TDEE, body fat and more.
BMR Calculator
Calculate your Basal Metabolic Rate using Mifflin-St Jeor formula.
TDEE Calculator
Calculate Total Daily Energy Expenditure for weight management.
Body Fat Calculator
Calculate body fat percentage using the US Navy method.
Water Intake Calculator
Calculate how much water you should drink daily based on your body.
Braces Cost Calculator
Estimate braces and Invisalign costs by type, age, and complexity — with insurance, HSA/FSA, and payment-plan math.
Dental Implant Cost Calculator
Estimate dental implant costs with prep procedures, see what insurance really pays, and compare implants vs bridges vs dentures over 25 years.
IVF Cost Calculator
Estimate IVF costs with add-ons, model cumulative success by age and cycles, and compare financing options.
Hair Transplant Cost Calculator
Estimate hair transplant costs by Norwood stage, graft count, and technique — with donor supply checks and lifetime cost math.
Drug Rehab Cost Calculator
Estimate rehab episode costs by level of care, model real insurance out-of-pocket, and compare ways to pay the gap.
Weight & Height Calculator
Calculate ideal weight range based on your height and age.
Health Dashboard
View all your health metrics in one comprehensive dashboard.
Math Calculators
Free math calculators for percentages, fractions, statistics and more.
Percentage Calculator
Calculate percentages, percentage increases, and percentage changes.
Fraction Calculator
Add, subtract, multiply, and divide fractions with step-by-step solutions.
Grade & GPA Calculator
Calculate grades and GPA from points, percentages, or letter grades.
Statistics Calculator
Calculate mean, median, mode, standard deviation, and more.
Percentage Increase Calculator
Calculate percentage increase between two values.
Ratio Calculator
Simplify ratios and calculate missing ratio values.
Tip Calculator
Calculate tip amounts and split bills among friends.
Discount Calculator
Calculate sale prices and savings from percentage discounts.
Date Calculator
Calculate days between dates, add or subtract days from a date.
Equation Solver
Solve linear equations with step-by-step solutions.
Quadratic Equation Solver
Solve quadratic equations and find x-intercepts.
Pythagorean Theorem Calculator
Calculate the sides of a right triangle using the Pythagorean theorem.
Scientific Notation Calculator
Convert numbers to and from scientific notation quickly.
Frequently Asked Questions
How many calculators does GM Calculator offer?
GM Calculator offers 51 free online calculators across 4 categories: Marketing, Finance, Health, and Math. All are completely free with no sign-up required.
Are these calculators really free to use?
Yes, absolutely. All calculators on GM Calculator are completely free to use with no hidden charges, no subscription fees, and no sign-up requirements. Just enter your numbers and get instant results.
How accurate are the calculators?
Our calculators use verified formulas from medical, financial, and mathematical standards. Health calculators use formulas like Mifflin-St Jeor and Harris-Benedict. Financial calculators use standard compound interest and margin formulas. All results are precise to 2+ decimal places.
Can I use these calculators on my phone?
Yes, all GM Calculator calculators are fully responsive and work on any device — desktop, tablet, and mobile. The interface adapts to your screen size for a seamless experience.
Which calculator should I use first?
It depends on your needs! For marketing, try the ROAS Calculator. For finance, the Compound Interest Calculator is popular. For health, start with the BMR or TDEE Calculator. For math, the Percentage Calculator is a great all-rounder.