I typed 1.6 instead of 16 on a Jaipur trip. Tool said petrol money is like a flight ticket. I almost cancelled the plan. Then I looked at the mileage box and laughed in a sad way.
1.6 instead of 16 is a classic. The litre count explodes. Check the decimal.
The fuel cost calculator is three boxes. Distance in km. Mileage in km per litre. Fuel price per litre. Litres is distance divided by mileage. Money is litres times price. There is no fourth magic.
If mileage is ten times too small, money is ten times too big. That is the whole "crazy" report I get in mail.
How the crazy number is born
Say 240 km, 16 km/l, ₹100 a litre. Litres 15. Money ₹1,500. Highway may do better. That is the worked example on the tool.
Now type 1.6 km/l by missing a key. Litres become 150. Money ₹15,000. Same car, same road, same pump. Only a decimal.
Type 160 by adding a extra zero. Litres become 1.5. Money ₹150. You feel like a hypermiler. You are not. You will stop at the pump confused.
I have done both. The 1.6 one is more common because phone keyboards and a habit of typing 1.6 for something else. Or someone thinks the box is litres per km, the inverse, and types 0.06-looking nonsense.
This box is km per litre. The Indian dinner-table number. "Car gives 16." Not litres per 100 km like some European stickers. If you only know litres per 100, convert first. 6.25 L/100 km is about 16 km/l. Dont type 6.25 in this mileage box unless your car really gives 6.25 km per litre, which is a thirsty story.
Brochure 22 and real city 12 is the other crazy. Less explosive than 1.6, still enough to mess a budget. Type what you actually get. Last three tanks, km divided by litres, average. I do that on a notebook page in the car, ugly handwriting.
If you type 22 and the car gives 12, a 240 km trip looks ₹1,091 at ₹100. Real is ₹2,000. You are short at the pump. Not as dramatic as 15,000, but you still swear at the tool. The tool used your 22.
Check these three boxes in order
Distance first. One way or both ways. I forget return every other trip. 240 becomes 480 if I need back. Or I already put 240 as round trip. Decide. Write it on the chat with the cousin before you type.
If there is a extra 40 km inside the city at the destination, add it. Dont be poetic.
Mileage second. Look at the number. Is it between, say, 8 and 30 for a normal petrol car? 12 to 20 is a common human range for a lot of hatchbacks and sedans we drive. A big SUV in city can sit near 8 to 12. A diesel highway run can sit higher. 1.6 is almost always a typo for a car. 160 is almost always a typo. 0.16 is a cry for help.
Bike numbers can be 35 to 60. Still not 3.5 unless you missed a digit.
Fuel price third. Pump board today. Not last Diwali. ₹100 is a clean default on this page so the maths is pretty. Your city might be 96 or 104 or whatever this week is. Type the board. A ₹4 miss on 15 litres is ₹60. Not crazy. I still update it because I am picky.
If you typed price 1000 because you added a extra zero, money goes crazy even with correct 16 km/l. Same family of error. Check all three, not only mileage.
CNG people can use km per kg and price per kg. Same shape. A 1.6 vs 16 style typo still explodes.
I dont add toll. I dont add snacks. I dont add the extra litre you waste in traffic outside the mall. Add those in your head.
Honest mileage, not the sticker on the rear glass
ARAI sticker is a lab mood. Your AC, your right foot, your tyre pressure, your 2 kids and a suitcase, those are the real mood.
I use two mileages when a trip has city plus highway. I run the tool twice. City km at city km/l. Highway km at highway km/l. Add money. One blended number also works if you already know a blend.
Cold start short trips kill mileage. A 8 km school run is not the same km/l as a 240 km jaunt. Dont use the school-run average for a highway estimate. Dont use the highway average for a month of city errands.
I tried this on my last Udaipur run. Highway gave near 18. Inside Udaipur, 12. I had typed 18 for the whole 240 plus local. I was short. Not flight-ticket short. Annoyingly short.
Service due, dirty filter, underinflated tyres. Mileage drops. If the car suddenly shows 11 when it was 16, believe the tank, not the memory.
Company car vs personal. If you dont pay, you still might want the number for a claim. Use honest km. Claims people can smell 22 km/l on a city-only week.
If two cousins share a car and one types 16 and the other types 1.6, you get two budgets and a fight. Look at the screen together. Decimal.
When the result is crazy, a 30 second debug
Look at litres first, not rupees. Rupees just follow.
240 km at 16 km/l is 15 litres. You can do that in your head. 240/16 = 15. If the page says 150 litres, mileage is 1.6 or distance is 2400.
Does the tank even hold 150 litres? No normal hatchback does. That question saves people. I ask it now like a uncle.
If litres look fine and rupees look wild, price box is the villain.
If both look fine and you still feel the trip "cannot cost that", maybe you are used to a old ₹80 petrol memory. Price moved. The tool is not nostalgic.
Split the trip. If 4 people share, ₹1,500 / 4 is ₹375. Use the split bill tool after, if you want. Crazy total becomes a normal per-head if the litres were right.
240 km trip, how much petrol money is the calm version of this maths. This post is the panic version.
I also see people type mileage in the distance box and km in the mileage box. 16 km trip at 240 km/l. Litres become tiny. Money becomes snack money. Then they overfill and think I under-count. Swap check. Distance should look like a road. Mileage should look like a car claim.
Default fields are 240, 16, 100. If you hit calculate without changing and you dont have that trip, of course it is not your trip.
Habits so I dont do 1.6 again
I say the number out loud. "Sixteen kilometre per litre." If I hear "one point six" I stop.
I glance at litres. For 200 to 300 km, I expect roughly 12 to 25 litres on a ordinary petrol car. Outside that, I re-read boxes.
I keep last trip's litres in the car notes. If last similar trip was 14 litres and this estimate is 140, I know.
I dont use comma as decimal in a way the field rejects. 16.5 is 16.5. If I type 16,5 some browsers get confused. I use a point.
I update mileage after a highway trip if I want the next highway estimate tighter. I dont update it after one bad city week and then plan a 600 km run with that sulk number.
If the car is new and I have no idea, I start conservative. 12 for a petrol city-ish mix, then improve the number after a tank. Conservative means more litres, more money booked. Leftover cash at the pump is nicer than borrowing from the food budget.
I will not promise your car hits 16. I will not use a official test cycle chart. Your tank is the lab.
Estimate. Pump meter wins. This page does not know slopes, wind, and how long you idled at a railway crossing.
When the cost goes crazy, I dont redesign the formula. I look at the decimal. Most days that is the bug. The rest of the days it is return km I forgot, or a brochure fantasy.
Type 16 if you mean 16. Type 1.6 only if the vehicle truly drinks like that. Almost no cousin trip needs 1.6. I say that with love, and with the memory of a ₹15,000 petrol joke that was a missing zero.