Tool index
All tools
Every IFN utility in one place — 78 free tools and counting.
401(k) Calculator
Project your 401(k) balance at retirement with monthly compounding, your employer match, and catch-up contributions, then compare what-if contribution rates side by side.
529 College Savings Calculator
See what four years of college will cost when your child enrolls, how far your 529 gets you, and the monthly savings that closes the gap.
Age Calculator
Enter your date of birth to get your exact age in years, months, and days, with total days lived, a countdown to your next birthday, and the weekday you were born on.
Asphalt Calculator
Estimate hot-mix asphalt by the ton from your driveway dimensions, or count 50 lb cold-patch bags for a pothole repair. Includes overlay thickness guidance and editable local pricing.
Attic Insulation Calculator
Pick your IECC climate zone for the target R-value, enter your existing insulation, and the page figures how many inches to add, in blown-in or batt form, with DIY vs. contractor costs.
Auto Loan Payment Calculator
Estimate your monthly car payment, total interest, and how extra payments can shorten the loan.
Bathroom Exhaust Fan Size Calculator
Enter your bathroom's dimensions and fixtures, and the page works out the CFM the room requires under the HVI method, then adjusts for your duct run and rounds up to the fan size you should actually buy.
BMR Calculator
Calculate your Basal Metabolic Rate with the Mifflin-St Jeor equation, add your activity level, and get a daily calorie target.
Body Fat Calculator
Get your body fat percentage from the U.S. Navy tape method, see where it lands for your age, and find out how much fat you would need to lose to hit a target.
Calories Burned Calculator
Plan a warm-up, a run, and strength work as one session, with treadmill grade handled by exercise-physiology formulas instead of flat estimates.
Capital Gains Tax Calculator
See the full 2026 tax on your sale: short vs long-term, the day-366 timing math, NIIT, and a rough state estimate.
Car Maintenance Cost Calculator
Enter your odometer reading and yearly mileage. The page turns AAA's 2026 maintenance figure into a yearly budget for your car, a monthly savings target, and a five-year forecast that flags the years when tires and major service come due.
Carpet Calculator
Size carpet for rooms and staircases: strip layout, 12 ft vs 15 ft roll comparison, and cost per square yard.
Case Converter
Paste text once and get every case at the same time: camelCase, snake_case, kebab-case, and Title Case. Click any result to copy.
Character Counter
Live character, word, sentence, and reading-time counts as you type, with presets for X, meta descriptions, and more.
Christmas Light Calculator
Enter your roofline, tree, windows, doors and shrubs, pick a bulb type and style, and the page works out how many bulbs and strands the whole house takes, what the load is in amps and circuits, and what the season costs.
Coffee Brew Ratio Calculator
Pick a brew method and enter your water, coffee, or cup count. The page gives the matching dose, scales batches, and walks cold brew from concentrate to finished cups.
Concrete Block Calculator
Enter your wall's length and height, and the page works out how many blocks to order, how many pallets that means for delivery, the mortar and grout bags, the rebar for the grouted cores, and the cap blocks for the top course.
Concrete Calculator
Enter your slab, post, footing, step, or wall dimensions to get cubic yards, bag count, mixer batches, and a cost estimate before you buy.
Countertop Slab & Cost Calculator
Enter each countertop run as a rectangle, pick a slab size, and the page works out how many slabs you need, where the seams fall, and what each material costs installed.
Cups to Grams Converter
Convert cups to grams for 47 common ingredients, using real density data. Pick the ingredient, set the amount, get the weight.
Debt Payoff Calculator
Line up every debt, compare snowball, avalanche, and irregular-income payoff plans, and see what a consolidation loan would do.
Deck Cost Calculator
Price a deck from its size and material, get a full shopping list of boards, joists, and fasteners, and see the annualized cost of keeping it.
Drywall Calculator
Figure out how many drywall sheets a multi-room project needs, with door and window openings deducted.
Emergency Fund Calculator
Size your emergency fund from real spending, find the gap, and plan the monthly savings to close it.
EV Charging Cost Calculator
Compare home and public charging costs for your EV across four scenarios, then see the yearly savings against a gas car.
Fence Calculator
Plan a fence project: pick the type, set the length, add gates and corners, and get a materials list with a realistic cost range.
Final Grade Calculator
Work out what you need on the final to hit your target grade, see your current weighted grade across categories, or run a what-if table of exam scores.
Firewood Calculator
Size your firewood order: stacked dimensions to full cords, face-cord decoding by log length, and a true price-per-cord quote comparison.
First Home Buyer Planner
Enter the home price, loan type, closing costs, moving and furniture, and a cash reserve, and the page works out the total cash you need before closing, the monthly mortgage payment, and how many months of saving stand between you and the keys.
Flooring Calculator
Pick the right flooring with a 3-question quiz, then get box counts, waste allowance, and a full installed-cost estimate for any room.
Freelance Rate Calculator
Start from the annual income you want and work backwards to the hourly rate that covers it, with taxes, expenses, and unbilled hours included.
FSA Spend-Down Calculator
Enter your annual FSA election and what you have spent so far. The page works out what is left, how much of it is at risk, what you can carry over, and how much to spend each week before your deadline.
Furnace Size Calculator
Pick your city for its design temperature and heating degree days, and the page estimates your heating load, the furnace size it calls for, a heat pump size with auxiliary heat, and what each system costs to run for a year.
Generator Size Calculator
Build your appliance list and get the generator size you actually need: running watts plus the biggest starting surge, with headroom and a kVA to kW converter.
GPA Calculator
Add your courses and grades to get semester and cumulative GPA, weighted or unweighted, on a 4.0 or 5.0 scale.
Gravel Calculator
Estimate gravel by the layer: enter each layer's dimensions and material for cubic yards, tons, and delivered cost.
Ice Melt Calculator
Enter your driveway, walkway and steps, pick a deicer product and the pavement temperature, and the page works out how much you need per storm, how many bags that is, and what a whole season costs.
Job Offer Comparison Calculator
Compare up to four job offers on true total compensation: base, bonus, 401k match, PTO value, amortized signing bonus, and vested RSUs, side by side.
Lawn Fertilizer Calculator
Pick your grass type, enter your lawn size and bag details, and get a full-year nitrogen schedule: how much to apply each month, how many bags to buy, and what it costs.
Lease vs Buy Car Calculator
Compare leasing and buying the same car by net cost, not monthly payment, with a money-factor converter and a residual flip-point table.
Lumber Calculator
Turn a cut list of nominal lumber sizes into board feet, waste, and cost, with a nominal versus actual size reference.
Macro Calculator
Turn your stats into daily protein, carb, and fat targets in grams, tuned for cutting, maintaining, or lean bulking.
Mortgage Payoff Calculator
See how extra payments shorten your mortgage and what they save, or what investing that money could earn instead.
One Rep Max Calculator
Enter a weight and reps to estimate your one-rep max with four standard formulas, plus a full training-percentage table.
Overtime Pay Calculator
Estimate weekly overtime pay under federal or California rules, and check the overtime line on a pay stub.
Paint Calculator
Figure out how much paint a room really needs: wall area minus doors and windows, ceilings and trim, primer separate, rounded up to the cans stores actually sell.
Paver Patio Calculator
Add rectangles and circles for your patio, pick paver size and pattern. The page outputs pavers to buy, base gravel and sand tonnage, polymeric sand bags, edge restraint, and installed cost.
Paycheck Calculator
What actually lands in your bank account. 2026 federal brackets, Social Security and Medicare, all 50 states, and your pre-tax deductions — per paycheck.
Pizza Dough Calculator
Scale pizza dough by baker's percentage across four styles, convert yeast types, and check the thickness factor.
Propane Refill Days Calculator
Enter your tank size and gauge reading plus how much propane you use each day, and the page works out how many days you have until you should order, the date to order by, and how many gallons to ask for to reach a full 80% fill.
Protein Intake Calculator
Enter your weight and goal to get a daily protein target in grams, plus what that looks like as actual food.
Range Hood CFM Calculator
Enter your cooktop width and burner output, your kitchen size and duct run, and the page works out the CFM you need, the hood width and duct size to match it, and whether the job triggers a makeup air requirement.
Reading Level Calculator
Paste your text for instant readability scores from five formulas, a grade spectrum, and sentence-level highlighting of the hard parts.
Rebar Size & Quantity Calculator
Enter slab dimensions, bar size, and spacing. The page figures bar count with cover deducted, lap splices for bars over 20 ft, total length and weight, tie points, and cost.
Recipe Scaler
Scale any recipe up or down: paste the ingredient list, pick a factor, get baking-aware quantities.
Rent vs Buy Calculator
Find the year buying a home starts beating renting, with the true monthly cost laid bare.
Retaining Wall Block Calculator
Enter your wall length and exposed height, pick a block, and the page works out block count with the buried course included, base gravel and drain rock tonnage, caps, and material cost.
Road Trip Cost Calculator
Budget a road trip's fuel, tolls, hotel, and food, split it per person, and compare driving against flying or the train.
Roof Snow Load Calculator
Measure the snow on your roof, pick its condition, and the page works out the load in pounds per square foot, the total weight on the roof, and how that compares with the design load in your permit record, so you can decide whether to shovel.
Roofing Shingle Calculator
Figure out how many shingle bundles your roof needs, what the accessories cost, and whether DIY or a contractor pencils out better.
Running Pace Calculator
Solve for pace, time, or distance: fill any two and get the third, with splits, race presets, and heat and altitude correction.
Salary to Hourly Calculator
Enter your annual salary to find your hourly, weekly, and monthly pay, calculated from your real work hours instead of the standard 2,080-hour year.
Sales Commission Calculator
Model a real sales comp plan: base salary, quota, tiered commission rates, bonus, and draw, then see your OTE, actual payout at any attainment level, and commission per hour.
Savings Goal Calculator
Work out how long a savings goal takes at your monthly pace, or how much you need to set aside each month to hit a date.
Self-Employment Tax Calculator
Your full 2026 self-employment tax picture. Social Security and Medicare broken out, federal income tax stacked on top, and what to send each quarter.
Shoe Size Converter
Convert shoe sizes between US, UK, EU, and JP for men, women, and kids. Start from any size or your foot length in cm.
Siding Calculator
Figure how many squares, panels, and boxes of siding a house needs, with trim footage and an editable installed-cost estimate.
Sleep Cycle Calculator
Fall asleep and wake up at the end of a sleep cycle, not in the middle of one.
Snow Blower Size Calculator
Enter your driveway size, surface, typical storm and snow type, and the page picks a stage and clearing width, counts the passes, and estimates how long clearing takes.
Solar Panel Calculator
Enter monthly electricity use and peak sun hours. The page sizes your system in panels and kilowatts, checks it against your roof area, and estimates installed cost and payback.
Stair Calculator
Enter the floor-to-floor rise to get riser height, tread count, total run, stringer length, and an IRC compliance check, with a side-elevation diagram. L and U shapes included.
TDEE Calculator
Find your total daily energy expenditure with three published formulas, five activity levels, and adjustable fat-loss, maintenance, and muscle-gain targets.
Time Card Calculator
Turn a week of clock-in and clock-out times into regular hours, overtime hours, and gross pay.
Token Counter
Paste text to estimate token counts for GPT, Claude, and Gemini, with context-window usage and API cost estimates.
Wallpaper Calculator
Count wallpaper rolls the right way: drops cut one pattern repeat long, so the design lines up.
Whole House Humidifier Size Calculator
Enter your home's size, how tight the envelope is, and what heats it. The page works out the gallons per day a humidifier must deliver under AHRI Guideline F, then matches the load to a bypass, fan-powered, or steam unit.
Wood Stove Size Calculator
Enter your floor area, climate band and house details, and the page works out the heat output your stove needs, the size class to shop, how many cords you will burn in a season, and what that firewood costs.