Sister site
FormOasis
Free online calculators, each one built with Gravity Forms. Try any of them, then grab the template and put the same calculator on your own WordPress site.
How it works
- 01
Try the calculator
Every tool works right in the browser with live results. No sign-up.
- 02
Grab the template
Each calculator is an import-ready Gravity Forms form you can add to your own site.
- 03
Follow the build guide
A free field-by-field guide shows how it works, so you can change it or build your own.
81 calculators
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Home & DIY
AC / BTU sizing calculator
Air conditioner size for a room.
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Dates & Time
Age calculator
Exact age in years, months and days.
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Money & Loans
Amortization schedule
Payment-by-payment split of principal and interest.
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Home & DIY
Appliance electricity cost calculator
What an appliance costs to run per month.
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Money & Loans
Auto loan calculator
Monthly car payment from price, down payment, rate and term.
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Money & Loans
Auto loan refinance calculator
Your new car payment and how much you save by refinancing your auto loan.
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Life & Planning
Baby cost estimator
First-year baby costs by category.
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Health & Fitness
BMI calculator
Body mass index from height and weight.
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Health & Fitness
Body fat percentage calculator
Body fat estimate from tape measurements.
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Business
Break-even calculator
Units to sell before a product makes money.
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Dates & Time
Business days calculator
Working days between two dates.
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Auto & Travel
Car depreciation calculator
Expected value of a car after some years.
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Money & Loans
Closing cost estimator
Typical fees due at closing for a home purchase.
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Life & Planning
Coffee brew ratio calculator
Grams of coffee and water for your brew.
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Money & Loans
Compound interest calculator
Growth of a deposit with regular contributions.
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Home & DIY
Concrete calculator
Cubic yards and bags for slabs and footings.
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Math & Convert
Cooking measurement converter
Cups, tablespoons, grams and ounces.
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Dates & Time
Countdown calculator
Days, weeks, months, hours and business days until a date.
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Business
CPM & ad revenue calculator
Revenue from impressions and CPM.
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Money & Loans
Credit card payoff calculator
How long a balance takes to clear at a given monthly payment.
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Health & Fitness
Daily calorie calculator (BMR / TDEE)
Calories to maintain, lose or gain weight.
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Dates & Time
Day of the week finder
Which weekday any date falls on.
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Dates & Time
Days between dates calculator
Days, weeks and months between two dates.
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Math & Convert
Discount calculator
Sale price after a discount.
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Money & Loans
Emergency fund calculator
How many months of expenses to set aside.
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Auto & Travel
EV charging cost calculator
Cost to charge from battery size and rate.
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Money & Loans
FAFSA SAI & Pell Grant calculator
Estimate the 2027–28 Student Aid Index and Pell Grant from the federal formula, for dependent and independent students.
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Home & DIY
Fence materials calculator
Posts, rails and pickets for a fence run.
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Business
Freelance hourly rate calculator
The rate that covers your income goal and costs.
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Life & Planning
Gift budget planner
Spread a holiday budget across a list.
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Math & Convert
GPA calculator
Grade point average from grades and credits.
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Math & Convert
Grade calculator
Test score percentage and what you need on the final.
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Health & Fitness
Heart-rate zones calculator
Training zones from age and resting heart rate.
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Money & Loans
Hourly to salary converter
Hourly wage to annual salary and back.
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Dates & Time
Hours worked calculator
Timesheet hours from clock-in and clock-out.
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Health & Fitness
Ideal weight range
Healthy weight range for your height.
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Money & Loans
Inflation calculator
What a dollar amount is worth in another year.
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Health & Fitness
IVF due date calculator
Weeks pregnant and days until your due date after an embryo transfer.
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Auto & Travel
Lease vs. buy calculator
Total cost of leasing against buying.
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Health & Fitness
Macro split calculator
Protein, carbs and fat grams for a calorie target.
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Money & Loans
Mortgage affordability calculator
How much house your income and debts support.
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Money & Loans
Mortgage calculator
Estimate your monthly payment including property tax and insurance.
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Money & Loans
Mortgage payoff calculator
How much interest and time you save by paying extra on your mortgage.
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Home & DIY
Moving cost estimator
Rough moving cost by distance and home size.
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Auto & Travel
MPG calculator
Miles per gallon from a fill-up.
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Home & DIY
Mulch & gravel calculator
Cubic yards to cover an area at a depth.
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Health & Fitness
Ovulation calculator
Fertile window from cycle length.
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Home & DIY
Paint calculator
Gallons needed for a room, coats included.
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Life & Planning
Party food & drink planner
How much food and drink for a headcount.
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Math & Convert
Percentage calculator
Percent of, percent change and percent difference.
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Money & Loans
Personal loan calculator
Monthly payment and total interest on a personal loan.
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Life & Planning
Pet age calculator
Dog or cat age in human years.
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Home & DIY
Pool chemical dosing calculator
Chlorine, acid and shock to add by volume.
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Home & DIY
Pool volume calculator
Gallons in a pool from its shape and depth.
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Health & Fitness
Pregnancy due date calculator
Due date from last period or conception date.
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Money & Loans
Present & future value calculator
Grow a sum forward or discount it back at a rate, with regular contributions.
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Business
Profit margin & markup calculator
Margin, markup and price from cost.
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Math & Convert
Ratio & aspect ratio calculator
Scale a ratio or find a missing dimension.
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Math & Convert
Recipe scaler
Ingredient amounts for more or fewer servings.
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Money & Loans
Refinance break-even calculator
Months until a refinance pays for its closing costs.
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Money & Loans
Rent vs. buy calculator
Compare the long-run cost of renting and owning.
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Money & Loans
Retirement savings calculator
Projected nest egg from contributions and returns.
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Business
ROI calculator
Return on investment as a percentage.
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Home & DIY
Roofing squares calculator
Roofing squares and bundles from roof area.
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Health & Fitness
Running pace calculator
Pace, time or distance from the other two.
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Money & Loans
Sales tax calculator
Price with tax added, or tax backed out.
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Money & Loans
Savings goal calculator
What to save each month to hit a target by a date.
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Business
Self-employment tax estimator
Rough self-employment tax on net earnings.
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Health & Fitness
Sleep cycle calculator
Bedtimes that end on a full sleep cycle.
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Home & DIY
Solar savings calculator
Payback years and savings from a solar install.
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Health & Fitness
Steps to miles converter
Steps to distance from your stride.
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Money & Loans
Take-home paycheck estimator
Net pay after taxes and deductions.
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Home & DIY
Tile & flooring calculator
Square feet and boxes, with waste allowance.
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Money & Loans
Tip & split calculator
Tip and per-person total for the table.
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Auto & Travel
Tire size comparison
Diameter and speedometer change between tire sizes.
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Auto & Travel
Travel budget calculator
Trip budget from nights, meals and activities.
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Auto & Travel
Trip fuel cost calculator
Fuel cost for a trip from distance, MPG and price.
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Math & Convert
Unit converter
Length, weight, volume and temperature.
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Home & DIY
Wallpaper calculator
Rolls needed for a room.
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Health & Fitness
Water intake calculator
Daily water from weight and activity.
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Life & Planning
Wedding budget calculator
Budget split across the usual wedding lines.